Preface Introduction Functions SIPROTEC Mounting and Commissioning Multi-Functional Protective Relay with Local Control Technical Data 7SJ62/63/64 Literature Appendix V4.6 Glossary 7SJ63 V4.7 Manual C53000-G1140-C147-A Index 1 2 3 4 A Disclaimer of liability Copyright We have checked the contents of this manual against the hardware and software described. However, deviations from the description cannot be completely ruled out, so that no liability can be accepted for any errors or omissions contained in the information given. Copyright (c) Siemens AG 2015. All rights reserved. The information given in this document is reviewed regularly and any necessary corrections will be included in subsequent editions. We appreciate any suggested improvements. We reserve the right to make technical improvements without notice. Document version 04.64.01 Edition 07.2015 Dissemination or reproduction of this document, or evaluation and communication of its contents, is not authorized except where expressly permitted. Violations are liable for damages. All rights reserved, particularly for the purposes of patent application or trademark registration. Registered Trademarks SIPROTEC, SINAUT, SICAM and DIGSI are registered trademarks of Siemens AG. Other designations in this manual might be trademarks whose use by third parties for their own purposes would infringe the rights of the owner. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 3 Preface Purpose of this Manual This manual describes the functions, operation, installation, and commissioning of the device 7SJ62/63/64. In particular, one will find: * Information on the Device Configuration and a description of the device functions and setting options Chapter 2; * Instructions for mounting and commissioning Chapter 3; * List of technical data Chapter 4; * As well as a compilation of the most significant data for experienced users in Appendix A. For general information on operation and configuration of SIPROTEC 4 devices, please refer to the SIPROTEC System Description /1/. Target Audience Protection engineers, commissioning engineers, personnel concerned with adjustment, checking, and service of selective protective equipment, automatic and control facilities, and personnel of electrical facilities and power plants. Applicability of this Manual This manual is valid for: SIPROTEC 4 Multi-Functional Protective Relay with Local Control 7SJ62/63/64 firmware version V4.6 anf for 7SJ63 firmware version V4.7. The functionality of the devices 7SJ63 V4.6 and V4.7 is identical. 7SJ63 firmware versions V4.7 are actual maintenance versions. Indication of Conformity SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 This product complies with the directive of the Council of the European Communities on the approximation of the laws of the Member States relating to electromagnetic compatibility (EMC Council Directive 89/336/EEC) and concerning electrical equipment for use within specified voltage limits (Low-voltage directive 73/23 EEC). This conformity has been proved by tests performed according to Article 10 of the Council Directive in agreement with the generic standards EN 61000-6-2 and EN 61000-6-4 (for EMC directive) and with the standard EN 60255-6 (for Low Voltage Directive) by Siemens. AG. This device is designed and manufactured for application in industrial environment. The product conforms with the international standards of IEC 60255 and the German standard VDE 0435. 4 Preface Further standards IEEE Std C37.90-* Additional Support Should further information on the System SIPROTEC 4 be desired or should particular problems arise which are not covered sufficiently for the purchaser's purpose, the matter should be referred to the local Siemens representative. Training Courses Individual course offerings may be found in our Training Catalogue, or questions may be directed to our training centre in Nuremberg. Instructions and Warnings The warnings and notes contained in this manual serve for your own safety and for an appropriate lifetime of the device. Please observe them! The following indicators and standard definitions are used: DANGER indicates that death, severe personal injury or substantial property damage will result if proper precautions are not taken. Warning indicates that death, severe personal injury or substantial property damage can result if proper precautions are not taken. Caution indicates that minor personal injury or property damage can result if proper precautions are not taken. This particularly applies to damage on or in the device itself and consequential damage thereof. Note indicates information about the device or respective part of the instruction manual which is essential to highlight. 5 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 Preface WARNING! When operating an electrical device, certain parts of the device inevitably have dangerous voltages. Failure to observe these precautions can result in fatality, personal injury, or extensive material damage. Only qualified personnel shall work on and around this equipment. It must be thoroughly familiar with all warnings and safety notices of this manual as well as with the applicable safety regulations. The successful and safe operation of this device is dependent on proper handling, installation, operation, and maintenance by qualified personnel under observance of all warnings and hints contained in this manual. In particular the general erection and safety regulations (e.g. IEC, DIN, VDE, EN or other national and international standards) regarding the correct use of hoisting gear must be observed. Definition QUALIFIED PERSONNEL For the purpose of this instruction manual and product labels, a qualified person is one who is familiar with the installation, construction and operation of the equipment and the hazards involved. In addition, he has the following qualifications: * Is trained and authorized to energize, de-energize, clear, ground and tag circuits and equipment in accordance with established safety practices. * Is trained in the proper care and use of protective equipment in accordance with established safety practices. * Is trained in rendering first aid. Typographic and Graphical Conventions To designate terms which refer in the text to information of the device or for the device, the following fonts are used: Parameter names Designators of configuration or function parameters which may appear word-forword in the display of the device or on the screen of a personal computer (with operation software DIGSI), are marked in bold letters of a monospace type style. This also applies to header bars for selection menus. 1234A Parameter addresses have the same character style as parameter names. Parameter addresses contain the suffix A in the overview tables if the parameter can only be set in DIGSI via the option Display additional settings. Parameter Conditions possible settings of text parameters, which may appear word-for-word in the display of the device or on the screen of a personal computer (with operation software DIGSI), are additionally written in italics. This also applies to header bars for selection menus. Annunciations" Designators for information, which may be output by the relay or required from other devices or from the switch gear, are marked in a monospace type style in quotation marks. Deviations may be permitted in drawings and tables when the type of designator can be obviously derived from the illustration. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 6 Preface The following symbols are used in drawings: Device-internal logical input signal Device-internal logical output signal Internal input signal of an analog quantity External binary input signal with number (binary input, input indication) External binary output signal with number (device indication) External binary output signal with number (device indication) used as input signal Example of a parameter switch designated FUNCTION with the address 1234 and the possible settings ON and OFF Besides these, graphical symbols are used according to IEC 60617-12 and IEC 60617-13 or symbols derived from these standards. Some of the most frequently used are listed below: 7 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 Preface Input signal of an analog quantity AND gate OR gate Exclusive-OR gate (antivalence): output is active, if only one of the inputs is active Equivalence: output is active, if both inputs are active or inactive at the same time Dynamic inputs (edge-triggered) above with positive, below with negative edge Formation of one analog output signal from a number of analog input signals Limit stage with setting address and parameter designator (name) Timer (pickup delay T, example adjustable) with setting address and parameter designator (name) Timer (dropout delay T, example non-adjustable) Dynamic triggered pulse timer T (monoflop) Static memory (RS-flipflop) with setting input (S), resetting input (R), output (Q) and inverted output (Q) SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 8 Preface 9 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 Contents 1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 1.1 Overall Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 1.2 Application Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 1.3 Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 2 Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 2.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 2.1.1 2.1.1.1 2.1.1.2 2.1.1.3 Functional Scope. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 36 36 38 2.1.2 2.1.2.1 2.1.2.2 2.1.2.3 2.1.2.4 Device, General Settings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 41 41 42 42 2.1.3 2.1.3.1 2.1.3.2 2.1.3.3 2.1.3.4 Power System Data 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 44 44 48 49 2.1.4 2.1.4.1 2.1.4.2 2.1.4.3 2.1.4.4 Oscillographic Fault Records. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 50 50 51 51 2.1.5 2.1.5.1 2.1.5.2 2.1.5.3 2.1.5.4 Settings Groups. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 52 52 53 53 2.1.6 2.1.6.1 2.1.6.2 2.1.6.3 2.1.6.4 Power System Data 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 54 54 57 57 2.1.7 2.1.7.1 2.1.7.2 2.1.7.3 EN100-Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 58 58 58 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 8 Contents 2.2 Overcurrent Protection 50, 51, 50N, 51N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 2.2.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 2.2.2 Definite High-Current Elements 50-2, 50N-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 2.2.3 Definite Overcurrent Elements 50-1, 50N-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 2.2.4 Inverse Time Overcurrent Elements 51, 51N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 2.2.5 Dynamic Cold Load Pickup Function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 2.2.6 Inrush Restraint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 2.2.7 Pickup Logic and Tripping Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 2.2.8 Two-Phase Time Overcurrent Protection (non-directional only) . . . . . . . . . . . . . . . . . . . . . 73 2.2.9 Busbar Protection by Use of Reverse Interlocking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 2.2.10 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 2.2.11 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 2.2.12 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 2.3 Directional Overcurrent Protection 67, 67N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 2.3.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 2.3.2 Definite Time, Directional High-set Elements 67-2, 67N-2 . . . . . . . . . . . . . . . . . . . . . . . . . 90 2.3.3 Definite Time, Directional Overcurrent Elements 67-1, 67N-1. . . . . . . . . . . . . . . . . . . . . . . 92 2.3.4 Inverse Time, Directional Overcurrent Protection Elements 67-TOC, 67N-TOC. . . . . . . . . 94 2.3.5 Interaction with the Fuse Failure Monitor (FFM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 2.3.6 Dynamic Cold Load Pickup Function. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 2.3.7 Inrush Restraint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 2.3.8 Determination of Direction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 2.3.9 Reverse Interlocking for Double End Fed Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 2.3.10 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 2.3.11 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 2.3.12 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 2.4 Dynamic Cold Load Pickup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 2.4.1 Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 2.4.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 2.4.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 2.4.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 2.5 Single-Phase Overcurrent Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 2.5.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 2.5.2 High-impedance Ground Fault Unit Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 2.5.3 Tank Leakage Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 2.5.4 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 2.5.5 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 2.5.6 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 9 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 Contents 2.6 Voltage Protection 27, 59 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 2.6.1 Measurement Principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 2.6.2 Overvoltage Protection 59 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 2.6.3 Undervoltage Protection 27 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 2.6.4 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 2.6.5 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 2.6.6 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 2.7 Negative Sequence Protection 46 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 2.7.1 Definite Time element 46-1, 46-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 2.7.2 Inverse Time element 46-TOC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 2.7.3 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 2.7.4 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 2.7.5 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 2.8 Motor Protection (Motor Starting Protection 48, Motor Restart Inhibit 66). . . . . . . . . . . . . 154 2.8.1 2.8.1.1 2.8.1.2 Motor Starting Protection 48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 2.8.2 2.8.2.1 2.8.2.2 Motor Restart Inhibit 66 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 2.8.3 2.8.3.1 2.8.3.2 Motor (Motor Starting Protection 48, Motor Restart Inhibit 66) . . . . . . . . . . . . . . . . . . . . . 169 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 2.9 Frequency Protection 81 O/U . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 2.9.1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 2.9.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172 2.9.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174 2.9.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174 2.10 Thermal Overload Protection 49 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 2.10.1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 2.10.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179 2.10.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184 2.10.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 10 Contents 2.11 Monitoring Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185 2.11.1 2.11.1.1 2.11.1.2 2.11.1.3 2.11.1.4 2.11.1.5 2.11.1.6 2.11.1.7 2.11.1.8 Measurement Supervision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hardware Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Software Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Monitoring of the Transformer Circuits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Measurement Voltage Failure Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185 185 185 186 186 189 191 192 193 2.11.2 2.11.2.1 2.11.2.2 2.11.2.3 2.11.2.4 Trip Circuit Supervision 74TC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193 194 197 197 197 2.11.3 2.11.3.1 Malfunction Responses of the Monitoring Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198 Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198 2.12 Ground Fault Protection 64, 67N(s), 50N(s), 51N(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 2.12.1 Voltage Element 64 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 2.12.2 Current Elements 50Ns, 51Ns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 201 2.12.3 Determination of Direction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 2.12.4 Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205 2.12.5 Ground Fault Location (in isolated systems) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 2.12.6 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209 2.12.7 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217 2.12.8 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 2.13 Intermittent Ground Fault Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 2.13.1 Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 2.13.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226 2.13.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227 2.13.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227 2.14 Automatic Reclosing System 79 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228 2.14.1 Program Execution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229 2.14.2 Blocking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233 2.14.3 Status Recognition and Monitoring of the Circuit Breaker . . . . . . . . . . . . . . . . . . . . . . . . . 235 2.14.4 Controlling Protective Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237 2.14.5 Zone Sequencing (not available for models 7SJ6***-**A**-) . . . . . . . . . . . . . . . . . . . . . . . 239 2.14.6 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 2.14.7 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247 2.14.8 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252 2.15 Fault Locator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254 2.15.1 Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254 2.15.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256 2.15.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256 2.15.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256 11 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 Contents 2.16 Breaker Failure Protection 50BF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257 2.16.1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257 2.16.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259 2.16.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 2.16.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 2.17 Flexible Protection Functions (7SJ64 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262 2.17.1 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262 2.17.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267 2.17.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272 2.17.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 2.18 Reverse-Power Protection Application with Flexible Protection Function . . . . . . . . . . . . . 274 2.18.1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274 2.18.2 Implementation of the Reverse-Power Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278 2.18.3 Configuring the Reverse-Power Protection in DIGSI. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280 2.19 Synchronism and Voltage Check 25 (7SJ64 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283 2.19.1 2.19.1.1 2.19.1.2 2.19.1.3 2.19.1.4 2.19.1.5 2.19.1.6 2.19.1.7 2.19.1.8 2.19.1.9 2.19.1.10 SYNC Function group 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Synchrocheck . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Synchronous / Asynchronous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . De-energized Switching. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Direct Command / Blocking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SYNC Function Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Interaction with Control, AR and External Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.20 Temperature Detection via RTD Boxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301 2.20.1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301 2.20.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302 2.20.3 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304 2.20.4 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309 283 283 286 287 288 289 289 290 292 298 299 2.21 Phase Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310 2.21.1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310 2.21.2 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .311 2.22 Function Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312 2.22.1 Pickup Logic for the Entire Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312 2.22.2 Tripping Logic of the Entire Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312 2.22.3 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 12 Contents 2.23 Auxiliary Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314 2.23.1 2.23.1.1 2.23.1.2 Commissionig Aids with Browser (7SJ64 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316 2.23.2 2.23.2.1 2.23.2.2 2.23.2.3 Message Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . LED Display and Binary Outputs (output relays) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Information on the Integrated Display (LCD) or Personal Computer . . . . . . . . . . . . . . . . . Information to a Substation Control Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317 317 318 319 2.23.3 2.23.3.1 2.23.3.2 2.23.3.3 2.23.3.4 Statistics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Circuit-Breaker Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320 320 321 328 330 2.23.4 2.23.4.1 2.23.4.2 2.23.4.3 Measurement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Display of Measured Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Transfer of Measured Values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331 331 333 333 2.23.5 2.23.5.1 2.23.5.2 2.23.5.3 2.23.5.4 Average Measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335 335 335 335 336 2.23.6 2.23.6.1 2.23.6.2 2.23.6.3 2.23.6.4 Min/Max Measurement Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336 336 336 337 337 2.23.7 2.23.7.1 2.23.7.2 2.23.7.3 Set Points for Measured Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339 339 340 340 2.23.8 2.23.8.1 2.23.8.2 2.23.8.3 Set Points for Statistic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341 341 341 341 2.23.9 2.23.9.1 2.23.9.2 2.23.9.3 2.23.9.4 Energy Metering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342 342 342 342 342 2.23.10 2.23.10.1 Commissioning Aids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343 Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343 2.24 Protection for Single-phase Voltage Transformer Connection. . . . . . . . . . . . . . . . . . . . . . 345 2.24.1 Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345 2.24.2 Impacts on the Functionality of the Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346 2.24.3 Setting Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348 13 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 Contents 2.25 Breaker Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350 2.25.1 2.25.1.1 2.25.1.2 Control Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351 2.25.2 2.25.2.1 Types of Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352 2.25.3 2.25.3.1 Command Sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353 2.25.4 2.25.4.1 Interlocking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354 2.25.5 2.25.5.1 Command Logging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362 3 Mounting and Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364 3.1 Mounting and Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365 3.1.1 Configuration Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365 3.1.2 3.1.2.1 3.1.2.2 3.1.2.3 3.1.2.4 3.1.2.5 3.1.2.6 3.1.2.7 Hardware Modifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Switching Elements on the Printed Circuit Boards of Device 7SJ62 . . . . . . . . . . . . . . . . . Switching Elements on the Printed Circuit Boards of Device 7SJ63 . . . . . . . . . . . . . . . . . Switching Elements on the Printed Circuit Boards of Device 7SJ64 . . . . . . . . . . . . . . . . Interface Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Reassembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1.3 3.1.3.1 3.1.3.2 3.1.3.3 3.1.3.4 3.1.3.5 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 406 Panel Flush Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 406 Rack Mounting and Cubicle Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408 Panel Surface Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .411 Mounting with Detached Operator Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 412 Mounting without Operator Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413 3.2 Checking Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415 370 370 372 378 384 392 402 406 3.2.1 Checking Data Connections of Serial Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415 3.2.2 Checking System Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 418 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 14 Contents 3.3 Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 420 3.3.1 Test Mode and Transmission Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 421 3.3.2 Checking the System (SCADA) Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 421 3.3.3 Checking the Status of Binary Inputs and Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423 3.3.4 Tests for Circuit Breaker Failure Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 426 3.3.5 Checking User-Defined Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 427 3.3.6 Current, Voltage, and Phase Rotation Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 427 3.3.7 Test for High Impedance Protection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 429 3.3.8 Testing the Reverse Interlocking Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 429 3.3.9 Direction Check with Load Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 429 3.3.10 Polarity Check for Voltage Input V4 (only 7SJ64) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431 3.3.11 Ground Fault Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433 3.3.12 Polarity Check for Current Input IN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434 3.3.13 Checking the Temperature Measurement via RTD-Box . . . . . . . . . . . . . . . . . . . . . . . . . . 436 3.3.14 Measuring the Operating Time of the Circuit Breaker (only 7SJ64) . . . . . . . . . . . . . . . . . 437 3.3.15 Trip/Close Tests for the Configured Operating Devices . . . . . . . . . . . . . . . . . . . . . . . . . . 438 3.3.16 Creating Oscillographic Recordings for Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 439 3.4 Final Preparation of the Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 440 4 Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 442 4.1 General Device Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 444 4.1.1 Analog Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 444 4.1.2 Auxiliary Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 445 4.1.3 Binary Inputs and Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 446 4.1.4 Communication Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 448 4.1.5 Electrical Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 454 4.1.6 Mechanical Stress Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 455 4.1.7 Climatic Stress Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 456 4.1.8 Service Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 457 4.1.9 Certifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 457 4.1.10 Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 457 4.2 Definite Time Overcurrent Protection 50, 50N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 459 4.3 Inverse Time Overcurrent Protection 51, 51N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461 4.4 Directional Time Overcurrent Protection 67, 67N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 473 4.5 Inrush Restraint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 475 4.6 Dynamic Cold Load Pickup Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 476 4.7 Single-Phase Overcurrent Protection 50 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 477 4.8 Voltage Protection 27, 59 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 478 4.9 Negative Sequence Protection 46-1, 46-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 480 4.10 Negative Sequence Protection 46-TOC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 481 15 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 Contents 4.11 Motor Starting Protection 48 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 487 4.12 Motor Restart Inhibit 66 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 488 4.13 Frequency Protection 81 O/U . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 489 4.14 Thermal Overload Protection 49 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 490 4.15 Ground Fault Detection 64, 50Ns, 51Ns, 67Ns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 493 4.16 Intermittent Ground Fault Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 497 4.17 Automatic Reclosing System 79 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 498 4.18 Fault Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 499 4.19 Circuit Breaker Failure Protection 50BF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500 4.20 Flexible Protection Functions (7SJ64 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 501 4.21 Synchronism and Voltage Check 25 (7SJ64 only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 503 4.22 RTD Boxes for Temperature Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 505 4.23 User-defined Functions (CFC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 506 4.24 Additional Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .511 4.25 Breaker Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 517 4.26 Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 518 4.26.1 Panel Flush and Cubicle Mounting (Housing Size 1/3) . . . . . . . . . . . . . . . . . . . . . . . . . . . 518 4.26.2 Panel Flush and Cubicle Mounting (Housing Size 1/2) . . . . . . . . . . . . . . . . . . . . . . . . . . . 519 4.26.3 Panel Flush and Cubicle Mounting (Housing Size 1/1) . . . . . . . . . . . . . . . . . . . . . . . . . . . 520 4.26.4 Panel Surface Mounting (Housing Size 1/3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 521 4.26.5 Panel Surface Mounting (Housing Size 1/2). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 521 4.26.6 Panel Surface Mounting (Housing Size 1/1). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 522 4.26.7 Surface-mounted Housing with Detached Operator Panel or without Operator Panel (Housing Size 1/2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 523 4.26.8 Housing for Mounting with Detached Operator Panel or without Operator Panel (Housing Size 1/1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 524 4.26.9 Detached Operator Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 525 4.26.10 D-Subminiature Connector of Dongle Cable (Panel Flush or Cubicle Door Cutout) . . . . . 526 A Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 528 A.1 Ordering Information and Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 529 A.1.1 A.1.1.1 A.1.1.2 A.1.1.3 Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7SJ62 V4.6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7SJ63 V4.6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7SJ64 V4.6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A.1.2 Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 541 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 529 529 533 537 16 Contents A.2 Terminal Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 543 A.2.1 7SJ62 -- Housing for panel flush mounting or cubicle installation . . . . . . . . . . . . . . . . . . 543 A.2.2 7SJ62 -- Housing for Panel Surface Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 545 A.2.3 7SJ62 -- Interface assignment on housing for panel surface mounting . . . . . . . . . . . . . . 547 A.2.4 7SJ63 -- Housing for panel flush mounting or cubicle installation . . . . . . . . . . . . . . . . . . 549 A.2.5 7SJ631/2/3 -- Housing for panel surface mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 556 A.2.6 7SJ631/2/3 -- Interface assignment on housing for panel surface mounting . . . . . . . . . . 559 A.2.7 7SJ635/6 -- Housing for panel surface mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 561 A.2.8 7SJ635/6 -- Interface assignment on housing for panel surface mounting . . . . . . . . . . . 565 A.2.9 7SJ63 -- Housing with detached operator panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 567 A.2.10 7SJ63 -- Housing for Panel Surface Mounting without Operator Panel . . . . . . . . . . . . . . 574 A.2.11 7SJ64 -- Housing for Panel Flush Mounting or Cubicle Installation . . . . . . . . . . . . . . . . . 581 A.2.12 7SJ64 -- Housing for Panel Surface Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 586 A.2.13 7SJ64 -- Housing with Detached Operator Panel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 591 A.2.14 7SJ64 -- Housing for Panel Surface Mounting without Operator Panel . . . . . . . . . . . . . . 595 A.2.15 Connector Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 598 A.3 Connection Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 599 A.3.1 Connection Examples for 7SJ62 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 599 A.3.2 Connection Examples for 7SJ63 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 606 A.3.3 Connection Examples for 7SJ64 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 615 A.3.4 Connection example for high-impedance ground fault differential protection . . . . . . . . . . 625 A.3.5 Connection Examples for RTD-Box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 625 A.4 Current Transformer Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 627 A.4.1 Accuracy limiting factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 627 A.4.2 Class conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 628 A.4.3 Cable core balance current transformer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 629 A.5 Default Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 630 A.5.1 LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 630 A.5.2 Binary Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 630 A.5.3 Binary Output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 631 A.5.4 Function Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 632 A.5.5 Default Display. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 632 A.5.6 Pre-defined CFC Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 637 A.6 Protocol-dependent Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 640 A.7 Functional Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 641 A.8 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 644 A.9 Information List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 665 A.10 Group Alarms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 692 A.11 Measured Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 693 17 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 Contents Literature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 698 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 700 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 708 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 18 Contents 19 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 1 Introduction The device family SIPROTEC 7SJ62/63/64 devices is introduced in this section. An overview of the devices is presented in their application, characteristics, and scope of functions. 1.1 Overall Operation 21 1.2 Application Scope 25 1.3 Characteristics 28 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 20 1 Introduction 1.1 Overall Operation The SIPROTEC 7SJ62/63/64 are numerical, multi-functional, protective and control devices equipped with a powerful microprocessor. All tasks are processed digitally exclusively, from acquisition of measured values up to commands to the circuit breakers. Figure 1-1 illustrates the basic structure of the devices 7SJ62/63, Figure 1-2 illustrates the basic structure of the device 7SJ64. Analog Inputs The measuring inputs (MI) convert the currents and voltages coming from the instrument transformers and adapt them to the level appropriate for the internal processing of the device. The device provides four current inputs. Depending on the model, the device is also equipped with three or four voltage inputs. Three current inputs serve for input of the phase currents. Depending on the model, the fourth current input (IN) may be used for measuring the ground fault current IN (current transformer starpoint) or for a separate ground current transformer (for sensitive ground fault detection INs and directional determination of ground faults). Figure 1-1 21 Hardware structure of the numerical multi-functional protection device 7SJ62 and 7SJ63 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 1.1 Overall Operation Voltage inputs can either be used to measure the three phase-to-ground voltages, or two phase-to-phase voltages and the displacement voltage (VN voltage). It is also possible to connect two phase-to-phase voltages in open-delta connection. The four voltage transformers of 7SJ64 can either be applied for the input of 3 phaseto-ground voltages, one displacement voltage (VN voltage) or a further voltage for the synchronizing function. The analog input quantities are passed on to the input amplifiers (IA). The input amplifier IA stage provides high-resistance terminations for the analog input quantities. It consists of filters that are optimized for measured-value processing with regard to bandwidth and processing speed. The analog-to-digital (AD) stage consists of a multiplexor, an analog-to-digital (A/D) converter and of memory components for the transmission of digital signals to the microcomputer system. Figure 1-2 Microcomputer System Hardware structure of the numerical multi-functional device 7SJ64 Apart from processing the measured values, the microcomputer system (C) also executes the actual protection and control functions. They especially include: * Filtering and preparation of the measured quantities * Continuous monitoring of the measured quantities SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 22 1 Introduction * Monitoring of the pickup conditions for the individual protective functions * Interrogation of limit values and sequences in time * Control of signals for the logic functions * Output of control commands for switching devices * Recording of messages, fault data and fault values for analysis * Management of the operating system and the associated functions such as data recording, real-time clock, communication, interfaces, etc. * The information is provided via output amplifiers (OA). Binary Inputs and Outputs The computer system obtains external information through the binary input/output modules (inputs and outputs). The computer system obtains the information from the system (e.g remote resetting) or the external equipment (e.g. blocking commands). Outputs are, in particular, commands to the switchgear units and indications for remote signalling of important events and statuses. Front Elements With devices with integrated or detached operator panel, information such as messages related to events, states, measured values and the functional status of the device are provided via light-emitting diodes (LEDs) and a display screen (LCD) on the front panel. Integrated control and numeric keys in conjunction with the LCD facilitate interaction with the remote device. Via these elements all information of the device such as configuration and setting parameters, operating and fault messages, and measured values can be accessed. Setting parameters may be changed in the same way. In addition, control of circuit breakers and other equipment is possible from the front panel of the device. Serial Interfaces A serial PC interface on the front panel is provided for local communications with the device through a personal computer using the operating program DIGSI.This facilitates a comfortable handling of all device functions. A separate service interface can be provided for remote communication with the device via a personal computer using DIGSI. This interface is especially well suited for dedicated connection of the devices to the PC or for operation via a modem. The service interface can also be used to connect an RTD box (= resistance temperature detector) for entering external temperatures (e.g. for overload protection). The additional interface (only 7SJ64) is designed exclusively for connection of a RTD-Box (= resistance temperature detector) for entering external temperatures. All data can be transferred to a central control center or monitoring system via the serial system interface. This interface may be provided with various protocols and physical transmission schemes to suit the particular application. A further interface is provided for the time synchronization of the internal clock via external synchronization sources. Further communication protocols can be realized via additional interface modules. Over the operating or service interface you can serve the device (only with 7SJ64) from a distance or locally with a standard Browser. This can take place during the initial start-up, examination and also during the operation with the devices. For this the SIPROTEC 4 standard "Web monitor" is available. 23 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 1.1 Overall Operation Power Supply The before-mentioned function elements and their voltage levels are supplied with power by a power supplying unit (Vaux or PS). Voltage dips may occur if the voltage supply system (substation battery) becomes short-circuited. Usually, they are bridged by a capacitor (see also Technical Data). SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 24 1 Introduction 1.2 Application Scope The numerical, multi-functional SIPROTEC 4 7SJ62/63/64 are versatile devices designed for protection, control and monitoring of busbar feeders. The devices can be used for line protection in networks that are grounded, low-resistance grounded, ungrounded, or of a compensated neutral point structure. They are suited for networks that are radial or looped, and for lines with single or multi-terminal feeds. The devices are equipped with motor protection applicable for asynchronous machines of all sizes. The devices include the functions that are necessary for protection, monitoring of circuit breaker positions, and control of the circuit breakers in straight bus applications or breaker-and-a-half configurations; therefore, the devices can be universally employed. The devices provide excellent backup facilities of differential protective schemes of lines, transformers, generators, motors, and busbars of all voltage levels. Protective Functions Non-directional overcurrent protection (50, 50N, 51, 51N) is the basis of the device. There are two definite time overcurrent protective elements and one inverse time overcurrent protective element for phase and ground current. For inverse time overcurrent protective elements, several characteristics of different standards are provided. Alternatively, user-defined characteristics can be programmed. Depending on the version of the device that is ordered, the non-directional overcurrent protection can be supplemented with directional overcurrent protection (67, 67N), breaker failure protection (50BF), and sensitive ground fault detection for high-resistance ground faults. The highly sensitive ground fault detection can be directional or non-directional. In addition to the fault protection functions already mentioned, other protective functions are available. Some of them depend on the version of the device that is ordered. These additional functions include frequency protection (81O/U), overvoltage protection (59) and undervoltage protection (27), negative sequence protection (46) and overload protection (49) with start inhibit for motors (66/68) and motor starting protection (48), as well as automatic reclosing (79) which allows different reclosing cycles on overhead lines. The automatic reclosing system may also be connected externally. To ensure quick detection of the fault, the device is equipped with a fault locator. A protection feature can be ordered for the detection of intermittent ground faults which detects and accumulates transient ground faults. External detectors account for ambient temperatures or coolant temperatures (by means of an external RTD-box). Before reclosing after three-pole tripping 7SJ64 can verify the validity of the reclosure by voltage check and/or synchronous check. The synchronization function can also be controlled externally. Control Functions The device provides a control function which can be accomplished for activating and deactivating switchgears via the integrated operator panel, the system interface, binary inputs, and the serial port using a personal computer with DIGSI. The status of the primary equipment can be transmitted to the device via auxiliary contacts connected to binary inputs. The present status (or position) of the primary equipment can be displayed on the device, and used for interlocking or plausibility monitoring. The number of the operating equipment to be switched is limited by the binary inputs and outputs available in the device or the binary inputs and outputs allocated for the switch position indications. Depending on the primary equipment being con- 25 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 1.2 Application Scope trolled, one binary input (single point indication) or two binary inputs (double point indication) may be used for this process. The capability of switching primary equipment can be restricted by a setting associated with switching authority (Remote or Local), and by the operating mode (interlocked/non-interlocked, with or without password request). Processing of interlocking conditions for switching (e.g. switchgear interlocking) can be established with the aid of integrated, user-configurable logic functions. Messages and Measured Values; Recording of Event and Fault Data The operating messages provide information about conditions in the power system and the device. Measurement quantities and values that are calculated can be displayed locally and communicated via the serial interfaces. Device messages can be assigned to a number of LEDs on the front cover (allocatable), can be externally processed via output contacts (allocatable), linked with userdefinable logic functions and/or issued via serial interfaces. During a fault (system fault) important events and changes in conditions are saved in fault protocols (Event Log or Trip Log). Instantaneous fault values are also saved in the device and may be analized subsequently. Communication Serial interfaces are available for the communication with operating, control and memory systems. A 9-pole DSUB socket at the front panel is used for local communication with a personal computer. By means of the SIPROTEC operating software DIGSI, all operation and evaluation tasks can be executed via this user interface, such as specifying and modifying configuration parameters and settings, configuring user-specific logic functions, retrieving operational messages and measured values, inquiring device conditions and measured values, issuing control commands. Depending on the individual ordering variant, additional interfaces are located on the rear side of the device. They serve to establish an extensive communication with other digital operating, control and memory components: The service interface can be operated via electrical data lines or fiber optics and also allows communication via modem. For this reason, remote operation is possible via personal computer and the DIGSI operating software, e.g. to operate several devices via a central PC. The additional port (only 7SJ64) is designed exclusively for connection of a RTD-Box (= resistance temperature detector) for entering external temperatures. It can also be operated via data lines or fibre optic cables. The system interface ensures the central communication between the device and the substation controller. It can also be operated via data lines or fibre optic cables. For the data transfer Standard Protocols according IEC 60870 870-5-103 are available via the system port. The integration of the devices into the automation systems SINAUT LSA and SICAM can also take place with this profile. The EN-100-module allows the devices to be integrated in 100-Mbit-Ethernet communication networks in control and automation systems using protocols according to IEC61850. Besides control system integration, this interface enables DIGSI-communication and inter-relay communication via GOOSE. Alternatively, a field bus coupling with PROFIBUS FMS is available for SIPROTEC 4. The PROFIBUS FMS according to DIN 19245 is an open communication standard that has particularly wide acceptance in process control and automation engineering, with especially high performance. A profile has been defined for the PROFIBUS com- SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 26 1 Introduction munication that covers all of the information types required for protective and process control engineering. The integration of the devices into the power automation system SICAM can also take place with this profile. Besides the field-bus connection with PROFIBUS FMS, further couplings are possible with PROFIBUS DP and the protocols DNP3.0 and MODBUS. These protocols do not support all possibilities which are offered by PROFIBUS FMS. 27 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 1.3 Characteristics 1.3 Characteristics General Characteristics * Powerful 32-bit microprocessor system. * Complete digital processing and control of measured values, from the sampling of the analog input quantities to the initiation of outputs, for example, tripping or closing circuit breakers or other switchgear devices. * Total electrical separation between the internal processing stages of the device and the external transformer, control, and DC supply circuits of the system because of the design of the binary inputs, outputs, and the DC or AC converters. * Complete set of functions necessary for the proper protection of lines, feeders, motors, and busbars. * Easy device operation through an integrated operator panel or by means of a connected personal computer running DIGSI. * Continuous calculation and display of measured and metered values on the front of the device. * Storage of min/max measured values (slave pointer function) and storage of longterm mean values. * Recording of event and fault data for the last eight system faults (fault in a network) with real-time information as well as instantaneous values for fault recording for a maximum time range of 5 s. * Constant monitoring of the measurement quantities, as well as continuous self-diagnostics covering the hardware and software. * Communication with SCADA or substation controller equipment via serial interfaces through the choice of data cable, modem, or optical fibers. * Battery-buffered clock that can be synchronized with an IRIG-B (via satellite) or DCF77 signal, binary input signal, or system interface command. * Statistics: Recording of the number of trip signals instigated by the device and logging of currents switched off last by the device, as well as accumulated short circuit currents of each pole of the circuit breaker. * Operating Hours Counter: Tracking of operating hours of the equipment being protected. * Commissioning aids such as connection check, direction determination, status indication of all binary inputs and outputs, easy check of system interface and influencing of information of the system interface during test operation Time Overcurrent Protection 50, 51, 50N, 51N * Two definite time overcurrent protective elements and one inverse time overcurrent protective element for phase current and ground current IN or summation current 3I0; * Two-phase operation of the overcurrent protection (IA, IC) possible; * Different curves of common standards are available for 51 and 51N, or a userdefined characteristic; * Blocking capability e.g. for reverse interlocking with any element; * Instantaneous tripping by any overcurrent element upon switch onto fault is possible; * Second harmonic inrush restraint. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 28 1 Introduction Ground Fault Protection 50N, 51N * Two definite time overcurrent protective elements and one inverse time overcurrent protective element for high-resistance ground faults in grounded systems; * Different curves of common standards are available for 51 and 51N, or a userdefined characteristic; * Second harmonic inrush restraint; * Instantaneous tripping by any overcurrent element upon switch onto fault is possible. Directional Time Overcurrent Protection 67, 67N * Three directional time overcurrent elements for both phase protection and ground protection operate in parallel to the non-directional time overcurrent elements. Their pickup values and time delays can be set independently from the non-directional time overcurrent elements. * Fault direction with cross-polarized voltages and voltage memory. Dynamically unlimited direction sensitivity; * Fault direction is calculated phase-selectively and separately for phase faults, ground faults and summation current faults. Dynamic Cold Load Pick-up Function 50C, 50NC, 51C, 51NC, 67C, 67NC * Dynamic changeover of time overcurrent protection settings, e.g. when cold load conditions are anticipated; * Detection of cold load condition via circuit breaker position or current threshold; * Activation via automatic reclosure (AR) possible; * Start also possible via binary input. Single-Phase Overcurrent Protection * Evaluation of the measured current via the sensitive or insensitive ground current transformer; * Suitable as differential protection that includes the neutral point current on a transformer side, a generator side or a motor side or for a grounded reactor set; * As tank leakage protection against illegal leakage currents between transformer casing and ground. Voltage Protection 27, 59 * Two undervoltage elements 27-1 and 27-2 measuring positive sequence voltage or the smallest of the applying voltages; * Choice of current supervision for 27-1 and 27-2; * Two overvoltage elements 59-1 and 59-2 for separate detection of overvoltages for the largest voltage applied; in addition, detection of the negative sequence component; * For a single-phase connection, the connected single-phase phase-to-ground or phase-to-phase voltage is evaluated; * settable dropout ratio for all elements of the undervoltage and overvoltage protection. Negative Sequence Protection 46 29 * Evaluation of negative sequence component of the currents; * Two definite-time elements 46-1 and 46-2 and one inverse-time element 46-TOC; curves of common standards are available for 46-TOC. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 1.3 Characteristics Motor Starting Protection 48 * Inverse time tripping characteristic based on an evaluation of the motor starting current; * Definite time delay for blocked rotor. Motor Start Inhibit 66, 86 * Approximate replica of excessive rotor temperature; * Startup is permitted only if the rotor has sufficient thermal reserves for a complete startup; * Disabling of the start inhibit is possible if an emergency startup is required. Frequency Protection 81 O/U * Monitoring on undershooting (f<) and/or overshooting (f>) with 4 frequency limits and delay times that are independently adjustable; * Insensitive to harmonics and abrupt phase angle changes; * Adjustable undervoltage threshold. Thermal Overload Protection 49 * Thermal profile of energy losses (overload protection has total memory capability); * True r.m.s. calculation; * Adjustable thermal alarm level; * Adjustable alarm level based on current magnitude; * Additional time constant setting for motors to accommodate the motor at standstill; * Integration of ambient temperature or coolant temperature is possible via external temperature sensors and RTD-Box. Monitoring Functions * Availability of the device is greatly increased because of self-monitoring of the internal measurement circuits, power supply, hardware, and software; * Current transformer and voltage transformer secondary circuits are monitored using summation and symmetry check techniques * Trip circuit monitoring; * Phase rotation check. Ground Fault Detection 50N(s), 51N(s), 67N(s), 59N/64 * Displacement voltage is measured or calculated from the three phase voltages; * Determination of a faulty phase on ungrounded or grounded networks; * Two-element Ground Fault Detection: 50Ns-1 and 50Ns-2; * High sensitivity (as low as 1 mA); * Overcurrent element with definite time or inverse time delay; * One user-defined and two logarithmic-inverse current/time curves are available for inverse time O/C protection; * Direction determination with zero-sequence quantities (I0, V0), wattmetric ground fault direction determination; * Any element can be set as directional or non-directional -- forward sensing directional, or reverse sensing directional; * Directional characteristic can be adjustable; * Optionally applicable as additional ground fault protection. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 30 1 Introduction Intermittent Ground Fault Protection * Detects and accumulates intermittent ground faults; Automatic Reclosing 79 * Single-shot or multi-shot; * Tripping after configurable total time. * With separate dead times for the first and all succeeding shots; * Protective elements that initiate automatic reclosing are selectable. The choices can be different for phase faults and ground faults; * Different programs for phase and ground faults; * Interaction to time overcurrent protection element and ground fault elements. They can be blocked in dependence of the reclosing cycle or released instantaneously; * Synchronous reclosing is possible (only 7SJ64) in conjunction with the integrated synchronizing feature. Fault Location * Initiation by trip command, external command or dropout of pickup; * Fault distance is calculated and given in secondary ohms and miles, or kilometres. Breaker Failure Protection 50 BF * Checking current flow and/or evaluation of the circuit breaker auxiliary contacts; * Initiated by the tripping of any integrated protective element that trips the circuit breaker; * Initiation possible via a binary input from an external protective device; * Initiation possible via the integrated control function. Flexible Protection Functions (7SJ64 only) * Up to 20 protection functions which can be set individually to operate in three-phase or single-phase mode; * Any calculated or directly measured value can be evaluated on principle; * Standard protection logic function with definite time characteristic; * Internal and configurable pickup and dropout delay; * Modifiable message texts. Synchronism and Voltage Check 25 (7SJ64 only) * Verification of the synchronous conditions before reclosing after three-pole tripping; * Fast measuring of the voltage difference V, the phase angle difference and the frequency difference f; * Alternatively, check of the de-energized state before reclosing; * Switching possible for asynchronous system conditions with prediction of the synchronization time; * Settable minimum and maximum voltage; * Verification of the synchronous conditions or de-energized state also possible before the manual closing of the circuit breaker, with separate limit values; * Measurement also possible via transformer without external intermediate matching transformer; * Measuring voltages optionally phase-to-phase or phase-to-ground. 31 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 1.3 Characteristics RTD-Boxes * Detection of any ambient temperatures or coolant temperatures by means of RTDBoxes and external temperature sensors. Phase Rotation * Selectable ABC or ACB by setting (static) or binary input (dynamic). Circuit-Breaker Maintenance * Statistical methods to help adjust maintenance intervals for CB contacts according to their actual wear; * Several autonomous subfunctions are imlemented (I procedure, Ix procedure and 2P procedure); 7SJ64 also features the I2t procedure); * Acquisition and conditioning of measured values for all subfunctions operates phase-selective using one procedure-specific threshold per subfunction. User Defined Functions * Internal and external signals can be logically combined to establish user-defined logic functions; * All common Boolean operations are available for programming (AND, OR, NOT, Exclusive OR, etc.); * Time delays and limit value interrogation; * Processing of measured values, including zero suppression, adding a knee curve for a transducer input, and live-zero monitoring; * CFC debugging via browser connection (7SJ64 only). Breaker Control * Circuit breakers can be opened and closed via specific process control keys (models with graphic displays only), the programmable function keys on the front panel, via the system interface (e.g. by or SCADA), or via the front PC interface using a personal computer with DIGSI); * Circuit breakers are monitored via the breaker auxiliary contacts; * Plausibility monitoring of the circuit breaker position and check of interlocking conditions. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 32 1 Introduction 33 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2 Functions This chapter describes the various functions of the SIPROTEC 4 device 7SJ62/63/64. It shows the setting options to each function in maximum configuration and provides information on how to determine the setting values and, if required, formulas. The following information also allows you to specify which of the available functions to use. 2.1 General 36 2.2 Overcurrent Protection 50, 51, 50N, 51N 59 2.3 Directional Overcurrent Protection 67, 67N 87 2.4 Dynamic Cold Load Pickup 117 2.5 Single-Phase Overcurrent Protection 123 2.6 Voltage Protection 27, 59 134 2.7 Negative Sequence Protection 46 146 2.8 Motor Protection (Motor Starting Protection 48, Motor Restart Inhibit 66) 154 2.9 Frequency Protection 81 O/U 171 2.10 Thermal Overload Protection 49 175 2.11 Monitoring Functions 185 2.12 Ground Fault Protection 64, 67N(s), 50N(s), 51N(s) 200 2.13 Intermittent Ground Fault Protection 220 2.14 Automatic Reclosing System 79 228 2.15 Fault Locator 254 2.16 Breaker Failure Protection 50BF 257 2.17 Flexible Protection Functions (7SJ64 only) 262 2.18 Reverse-Power Protection Application with Flexible Protection Function 274 2.19 Synchronism and Voltage Check 25 (7SJ64 only) 283 2.20 Temperature Detection via RTD Boxes 301 2.21 Phase Rotation 310 2.22 Function Logic 312 2.23 Auxiliary Functions 314 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 34 2 Functions 35 2.24 Protection for Single-phase Voltage Transformer Connection 345 2.25 Breaker Control 350 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.1 General 2.1 General The settings associated with the various device functions can be modified using the operating or service interface in DIGSI on a PC. Some parameters may also be changed using the controls on the front panel of the device. The detailed procedure is described in the SIPROTEC 4 System /1/. 2.1.1 Functional Scope The 7SJ62/63/64 relay contains protection functions as well as many other functions. The hardware and firmware is designed for this scope of functions. Additionally, the control functions can be matched to the system requirements. Individual functions can be enabled or disabled during the configuration procedure. The interaction of functions may also be modified. 2.1.1.1 Description Configuration of Functions Example for the configuration of functional scope: A protected system consists of overhead lines and underground cables. Since automatic reclosing is only needed for the overhead lines, the automatic reclosing function is not configured or "Disabled" for the relays protecting the underground cables. The available protection and additional functions must be configured as Enabled or Disabled. For individual functions, a choice between several alternatives may be presented, as described below. Functions configured as Disabled are not processed by the 7SJ62/63/64. There are no messages, and corresponding settings (functions, limit values) are not queried during configuration. Note Available functions and default settings depend on the ordering code of the relay (see A.1 for details). 2.1.1.2 Setting Notes Setting of the Functional Scope Configuration settings can be entered using a PC and the software program DIGSI and transferred via the front serial port or the rear service interface. The operation via DIGSI is explained in the SIPROTEC 4 System Description. For changing configuration parameters in the device, password no.7 is required (for parameter set). Without the password, the settings may be read, but may not be modified and transmitted to the device. The functional scope with the available options is set in the Functional Scope dialog box to match plant requirements. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 36 2 Functions Special Characteristics Most settings are self-explanatory. However, special characteristics are described below. If the setting group change function has to be used, address 103 Grp Chge OPTION must be set to Enabled. In service, simple and fast changeover between up to four different groups of settings is possible Only one setting group may be selected and used if this option is Disabled. For the relay elements associated with non-directional overcurrent protection (separately for phase and ground), various tripping characteristics may be selected at addresses 112 Charac. Phase and 113 Charac. Ground. If only the definite time characteristic is desired, then Definite Time should be selected. Additionally, depending on the relay type ordered, various inverse time characteristics, based on either IEC (TOC IEC) standards or ANSI (TOC ANSI) standards, or user-defined characteristic are available for selection. The dropout behavior of the IEC and ANSI characteristics will be specified later with settings (addresses 1210 and 1310), however, for the user-defined characteristic you determine in address 112 and 113 whether to specify only the pickup characteristic (User Defined PU) or the pickup and the reset time characteristic (User def. Reset). The superimposed high-current element 50-2 or 50N-2 is available in all these cases. Time overcurrent protection can be disabled by setting the function to Disabled. For directional overcurrent protection, the same information that was entered for the non-directional overcurrent protection can be entered at addresses 115 67/67-TOC and 116 67N/67N-TOC. For (sensitive) ground fault detection, address 131 Sens. Gnd Fault is used to specify whether this function should be enabled with definite time tripping characteristics (Definite Time), a User Defined PU and two logarithmic inverse characteristics or disabled by setting to Disabled. For the intermittent ground fault protection specify in address 133 INTERM.EF the measured quantity (with Ignd, with 3I0 or with Ignd,sens.) which is to be used by this protection function. For negative sequence current protection, address 140 46 is used to specify whether the tripping characteristics should be Definite Time, TOC ANSI or TOC IEC, or whether the function is to be Disabled. Set in address 142 49 for the overload protection whether (With amb. temp.) or not (No ambient temp) the thermal replica of the overload protection will account for a coolant temperature or ambient temperature or whether the entire function is set to Disabled. The flexible protective functions (only 7S64) can be configured in parameter FLEXIBLE FUNC.. You can create max. 20 functions. This can be done by marking (setting ticks) the functions (see example in Section 2.18). If the marking (the tick) of a function is removed, all the settings and allocations previously made are lost. All the settings and locations are located in the default setting when a new marking of the function takes place. The setting of the flexible function is performed in DIGSI under Parameter", Additional Functions" and Settings". The allocation is performed, as usually, under Parameter" and Allocation". Up to four function groups are available for the synchronizing function. They are enabled in address 016x (x = 1 ... 4). Parameters 161 25 Function 1 to 164 25 Function 4 indicate whether a synchronizing function is to be Disabled or Enabled. The latter is determined by selecting the operating mode ASYN/SYNCHRON (closing takes place for asynchronous and synchronous conditions) or SYNCHROCHECK (corresponds to the classical synchro-check function). The function groups which are configured to be enabled via ASYN/SYNCHRON or SYNCHROCHECK 37 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.1 General are displayed when you select the synchronizing function; function groups set to Disabled are hidden. When using the trip circuit monitoring, there is the possibility to select at address 182 74 Trip Ct Supv if the trip circuit monitoring should work with two (2 Binary Inputs) or only with one binay input (1 Binary Input) or if the function will be configured as Disabled. If you want to detect an ambient temperature or a coolant temperature and e.g. send the information to the overload protection, specify in address 190 RTD-BOX INPUT the port to which the RTD-box is connected. In 7SJ62/63/64 port C (service port) is used for this purpose, for 7SJ64 either port C (service port) or port D (additional port). The number and transmission type of the temperature detectors (RTD = Resistance Temperature Detector) can be specified in address191 RTD CONNECTION: 6 RTD simplex or 6 RTD HDX (with one RTD-box) or 12 RTD HDX (with two RTD-boxes). Implementation examples are given in the Appendix (under "Connection Examples"). The settings in address 191 have to comply with those at the RTD-box (see Subsection 2.20.2, under RTD-box Settings"). Several options are available at address 172 52 B.WEAR MONIT for CB maintenance. This does in no way affect the basic functionality of summation current formation (I procedure), which does not require any additional settings and sums up the tripping currents of the trips initiated by the protection function. The Ix procedure creates the sum of all tripping current powers and displays them as reference quantity. The 2P procedure continuously calculates the CB's remaining lifetime. The I2t procedure is only implemented in the 7SJ64. It forms the squared tripping currrent integrals over the arcing time and displays them as reference quantity. Section 2.23.3 provides more detailed information on CB maintenance procedures. 2.1.1.3 Addr. Settings Parameter Setting Options Default Setting Comments 103 Grp Chge OPTION Disabled Enabled Disabled Setting Group Change Option 104 OSC. FAULT REC. Disabled Enabled Disabled Oscillographic Fault Records 112 Charac. Phase Disabled Definite Time TOC IEC TOC ANSI User Defined PU User def. Reset Definite Time 50/51 113 Charac. Ground Disabled Definite Time TOC IEC TOC ANSI User Defined PU User def. Reset Definite Time 50N/51N SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 38 2 Functions Addr. Parameter Setting Options Default Setting Comments 115 67/67-TOC Disabled Definite Time TOC IEC TOC ANSI User Defined PU User def. Reset Definite Time 67, 67-TOC 116 67N/67N-TOC Disabled Definite Time TOC IEC TOC ANSI User Defined PU User def. Reset Definite Time 67N, 67N-TOC 117 Coldload Pickup Disabled Enabled Disabled Cold Load Pickup 122 InrushRestraint Disabled Enabled Disabled 2nd Harmonic Inrush Restraint 127 50 1Ph Disabled Enabled Disabled 50 1Ph 131 Sens. Gnd Fault Disabled Definite Time User Defined PU Log. inverse A Log. Inverse B Disabled (sensitive) Ground fault 133 INTERM.EF Disabled with Ignd with 3I0 with Ignd,sens. Disabled Intermittent earth fault protection 140 46 Disabled TOC ANSI TOC IEC Definite Time Disabled 46 Negative Sequence Protection 141 48 Disabled Enabled Disabled 48 Startup Supervision of Motors 142 49 Disabled No ambient temp With amb. temp. Disabled 49 Thermal Overload Protection 143 66 #of Starts Disabled Enabled Disabled 66 Startup Counter for Motors 150 27/59 Disabled Enabled Disabled 27, 59 Under/Overvoltage Protection 154 81 O/U Disabled Enabled Disabled 81 Over/Underfrequency Protection 161 25 Function 1 Disabled ASYN/SYNCHRON SYNCHROCHECK Disabled 25 Function group 1 162 25 Function 2 Disabled ASYN/SYNCHRON SYNCHROCHECK Disabled 25 Function group 2 163 25 Function 3 Disabled ASYN/SYNCHRON SYNCHROCHECK Disabled 25 Function group 3 164 25 Function 4 Disabled ASYN/SYNCHRON SYNCHROCHECK Disabled 25 Function group 4 39 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.1 General Addr. Parameter Setting Options Default Setting Comments 170 50BF Disabled Enabled Disabled 50BF Breaker Failure Protection 171 79 Auto Recl. Disabled Enabled Disabled 79 Auto-Reclose Function 172 52 B.WEAR MONIT Disabled Ix-Method 2P-Method I2t-Method Disabled 52 Breaker Wear Monitoring 180 Fault Locator Disabled Enabled Disabled Fault Locator 182 74 Trip Ct Supv Disabled 2 Binary Inputs 1 Binary Input Disabled 74TC Trip Circuit Supervision 190 RTD-BOX INPUT Disabled Port C Disabled External Temperature Input 191 RTD CONNECTION 6 RTD simplex 6 RTD HDX 12 RTD HDX 6 RTD simplex Ext. Temperature Input Connection Type - FLEXIBLE FUNC. 1..20 Flexible Function 01 Flexible Function 02 Flexible Function 03 Flexible Function 04 Flexible Function 05 Flexible Function 06 Flexible Function 07 Flexible Function 08 Flexible Function 09 Flexible Function 10 Flexible Function 11 Flexible Function 12 Flexible Function 13 Flexible Function 14 Flexible Function 15 Flexible Function 16 Flexible Function 17 Flexible Function 18 Flexible Function 19 Flexible Function 20 Please select Flexible Functions SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 40 2 Functions 2.1.2 Device, General Settings The device requires some general information. This may be, for example, the type of annunciation to be issued in the event a power system fault occurs. 2.1.2.1 Description Command-dependent Annunciations "No Trip - No Flag" The indication of messages masked to local LEDs, and the maintenance of spontaneous messages, can be made dependent on whether the device has issued a trip signal. This information is then not output if during a system disturbance one or more protection functions have picked up, but no tripping by the 7SJ62/63/64 resulted because the fault was cleared by a different device (e.g. on another line). These messages are then limited to faults in the line to be protected. The following figure illustrates the creation of the reset command for stored messages. When the relay drops off, stationary conditions (fault display Target on PU / Target on TRIP; Trip / No Trip) decide whether the new fault will be stored or reset. Figure 2-1 Spontaneous Annunciations on the Display 2.1.2.2 Creation of the reset command for the latched LED and LCD messages You can determine whether or not the most important data of a fault event is displayed automatically after the fault has occurred (see also Section Fault Events" in Chapter Additional Functions"). Setting Notes Fault Messages Pickup of a new protective function generally resets any previously set LED indications, so that only the latest fault is displayed at any time. It can be selected whether the stored LED displays and the spontaneous messages on the display appear upon renewed pickup, or only after a renewed trip signal is issued. In order to select the desired mode of display, select the submenu Device in the SETTINGS menu. The two alternatives 610 or FltDisp.LED/LCD (No trip - no flag") are selected at address Target on PU Target on TRIP. For devices with graphic display use parameter 611 Spont. FltDisp. to specify whether (YES) or not (NO) a spontaneous fault message will appear automatically on the display. For devices with text display such messages will appear after a system fault by any means. Selection of Default Display 41 Devices featuring 4-line display provide a number of predefined display pages. The start page of the default display, which will open after device startup, can be selected via parameter 640 Start image DD The available display pages are listed in the Appendix A.5. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.1 General 2.1.2.3 Addr. Settings Parameter Setting Options Default Setting Comments 610 FltDisp.LED/LCD Target on PU Target on TRIP Target on PU Fault Display on LED / LCD 611 Spont. FltDisp. YES NO NO Spontaneous display of flt.annunciations 640 Start image DD image 1 image 2 image 3 image 4 image 5 image 6 image 1 Start image Default Display 2.1.2.4 Information List No. Information Type of Information Comments - >Light on SP >Back Light on - Reset LED IntSP Reset LED - DataStop IntSP Stop data transmission - Test mode IntSP Test mode - Feeder gnd IntSP Feeder GROUNDED - Brk OPENED IntSP Breaker OPENED - HWTestMod IntSP Hardware Test Mode - SynchClock IntSP_Ev Clock Synchronization - Error FMS1 OUT Error FMS FO 1 - Error FMS2 OUT Error FMS FO 2 - Distur.CFC OUT Disturbance CFC 1 Not configured SP No Function configured 2 Non Existent SP Function Not Available 3 >Time Synch SP_Ev >Synchronize Internal Real Time Clock 5 >Reset LED SP >Reset LED 15 >Test mode SP >Test mode 16 >DataStop SP >Stop data transmission 51 Device OK OUT Device is Operational and Protecting 52 ProtActive IntSP At Least 1 Protection Funct. is Active 55 Reset Device OUT Reset Device 56 Initial Start OUT Initial Start of Device 67 Resume OUT Resume 68 Clock SyncError OUT Clock Synchronization Error 69 DayLightSavTime OUT Daylight Saving Time 70 Settings Calc. OUT Setting calculation is running 71 Settings Check OUT Settings Check 72 Level-2 change OUT Level-2 change 73 Local change OUT Local setting change 110 Event Lost OUT_Ev Event lost 113 Flag Lost OUT Flag Lost SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 42 2 Functions No. 125 Information Chatter ON Type of Information Comments OUT Chatter ON 140 Error Sum Alarm OUT Error with a summary alarm 144 Error 5V OUT Error 5V 145 Error 0V OUT Error 0V 146 Error -5V OUT Error -5V 147 Error PwrSupply OUT Error Power Supply 160 Alarm Sum Event OUT Alarm Summary Event 177 Fail Battery OUT Failure: Battery empty 178 I/O-Board error OUT I/O-Board Error 183 Error Board 1 OUT Error Board 1 184 Error Board 2 OUT Error Board 2 185 Error Board 3 OUT Error Board 3 186 Error Board 4 OUT Error Board 4 187 Error Board 5 OUT Error Board 5 188 Error Board 6 OUT Error Board 6 189 Error Board 7 OUT Error Board 7 191 Error Offset OUT Error: Offset 192 Error1A/5Awrong OUT Error:1A/5Ajumper different from setting 193 Alarm NO calibr OUT Alarm: NO calibration data available 194 Error neutralCT OUT Error: Neutral CT different from MLFB 220 CT Ph wrong OUT Error: Range CT Ph wrong 301 Pow.Sys.Flt. OUT Power System fault 302 Fault Event OUT Fault Event 303 sens Gnd flt OUT sensitive Ground fault 320 Warn Mem. Data OUT Warn: Limit of Memory Data exceeded 321 Warn Mem. Para. OUT Warn: Limit of Memory Parameter exceeded 322 Warn Mem. Oper. OUT Warn: Limit of Memory Operation exceeded 323 Warn Mem. New OUT Warn: Limit of Memory New exceeded 502 Relay Drop Out SP Relay Drop Out 510 Relay CLOSE SP General CLOSE of relay 43 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.1 General 2.1.3 Power System Data 1 2.1.3.1 Description The device requires certain basic data regarding the protected equipment, so that the device can adapt to its desired application. These may be, for instance, nominal power system and transformer data, measured quantity polarities and their physical connections, breaker properties (where applicable) etc. There are also certain parameters that are common to all functions, i.e. not associated with a specific protection, control or monitoring function. The following section discusses these data. 2.1.3.2 Setting Notes General This data can be entered directly on the device featuring an integrated or detached operator panel for parameters 209 PHASE SEQ., 210 TMin TRIP CMD, 211 TMax CLOSE CMD and 212 BkrClosed I MIN. Select the MAIN MENU by pressing the MENU key. Press the key to select SETTINGS and the X key to navigate to the settings selection. To obtain the Power System Data display, select the P.System Data 1 in the SETTINGS menu. In DIGSI double-click on Settings to display the relevant selection. A dialog box will open under the option P.System Data 1 with the tabs Power system, CTs, VTs and Breaker where you can configure the individual parameters. Thus the following Subsections are structured accordingly. Nominal Frequency The rated system frequency is set at address 214 Rated Frequency. The factory presetting in accordance with the model number must only be changed if the device will be employed for a purpose other than that which was planned when ordering. Phase Rotation Reversal Address 209 PHASE SEQ. is used to change the default phase sequence (A B C for clockwise rotation), if your power system permanently has an anti-clockwise phase sequence (A C B). A temporary reversal of rotation is also possible using binary inputs (see Section 2.21.2). Temperature Unit Address 276 TEMP. UNIT allows you to display the temperature values either in degree Celsius or in degree Fahrenheit. Polarity of Current Transformers At address 201 CT Starpoint, the polarity of the wye-connected current transformers is specified (the following figure applies correspondingly for two current transformers). This setting determines the measuring direction of the device (forwards = line direction). Modifying this setting also results in a polarity reversal of the ground current inputs IN or INS. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 44 2 Functions Figure 2-2 Voltage Connection Polarity of current transformers Address 213 specifies how the voltage transformers are connected. VT Connect. 3ph = Van, Vbn, Vcn means that three phase voltages in wye-connection are connected, VT Connect. 3ph = Vab, Vbc, VGnd signifies that two phase-to-phase voltages (V-connection) and VN are connected. The latter setting is also selected when only two phase-to-phase voltage transformers are utilized or when only the displaced voltage (zero sequence voltage) is connected to the device. Device 7SJ64 contains 4 voltage measuring inputs which enable further options besides the above-mentioned connection types: VT Connect. 3ph = Van,Vbn,Vcn,VGn is selected if the three phase voltages in wye-connection and VN are connected to the fourth voltage input of the device. Select VT Connect. 3ph = Van,Vbn,Vcn,VSy in case the fourth voltage input is used for the synchronizing function even if two phase-to-phase voltages (V-connection) are available on the primary side (since the voltages are connected to the device such that the device measures phase-ground voltages under symmetrical conditions). Note If the synchronization function is used for the connection to two-phase-to-phase voltages in V-connection (see above), the device cannot determine a zero sequence voltage. The function Directional Time Overcurrent Ground Protection", Directional Ground Fault Detection" and Fuse-Failure-Monitor (FFM)" must be disabled. Parameter 240 VT Connect. 1ph is set to specify that only one voltage transformer is connected to the devices. In this case the user defines which primary voltage is connected to which analog input. If one of the available voltages is selected, i.e. a setting unequal NO, setting of address 213 is no more relevant. Only address 240 is to be set. If parameter 240 VT Connect. 1ph is set to NO on the other hand, parameter 213 will apply. With 7SJ64 and single-phase voltage transformer connection the voltage connected to voltage input V4 is always interpreted as the voltage which is to be synchronized. 45 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.1 General Distance Unit Address 215 Distance Unit corresponds to the unit of length (km or Miles) applicable to fault locating. If a fault locator is not included with the device, or if the fault locating function is disabled, this setting has no effect on operation of the device. Changing the length unit will not result in an automatic conversion between the systems. Such conversions must be entered at the appropriate addresses. ATEX100 Address 235 ATEX100 allows that the requirements for the protection of explosionprotected motors with regard to thermal profiles is fulfilled. Set this parameter to YES to save all thermal replicas of devices 7SJ62/63/64 in the event of a power supply failure. After the supply voltage is restored the thermal profiles will resume operation using the stored values. Set the parameter to NO to reset the calculated overtemperatures of all thermal profiles to zero if the power supply fails. Two-phase Time Overcurrent Protection (Power System Data) Two-phase time overcurrent protection is used in isolated or resonant-grounded systems where three-phase devices are desired to coact with existing two-phase protection equipment. Parameter 250 50/51 2-ph prot can be set to specify whether the overcurrent protection operates in two or three phases. If set to ON, threshold comparison uses always the value 0A instead of the measured value for IB, so that phase B can not initiate a pick-up. All other functions operate however in three phases. Ground Fault Protection With address 613 Gnd O/Cprot. w. define whether ground fault protection either is to operate using measured values (Ignd (measured)) or the quantities calculated from the three phase currents (3I0 (calcul.)). In the first case, the measured quantity at the fourth current input is evaluated. In the latter case, the summation current is calculated from the three phase current inputs. If the device features a sensitive ground current input (measuring range starts at 1 mA), the ground fault protection always uses the calculated quantity 3I0. In this case, parameter 613 Gnd O/Cprot. w. is not available. Voltage Protection (Switchover of Characteristic Values) With three-phase connection, the fundamental harmonic component of the largest of the three phase-to-phase voltages (Vphph) is supplied to the overvoltage protection elements, or the negative sequence voltage (V2). With three-phase connection, undervoltage protection relies either on the positive sequence voltage V1 or the smallest of the phase-to-phase voltages Vphph. These specifications can be configured via parameter 614 OP. QUANTITY 59 and 615 OP. QUANTITY 27. If voltage transformers are connected single-phase, there is a direct comparison of measured values and thresholds, and the setting of characteristic values switchover is ignored. Nominal Values of Current Transformers (CTs) At addresses 204 CT PRIMARY and 205 CT SECONDARY, information is entered regarding the primary and secondary ampere ratings of the current transformers. It is important to ensure that the rated secondary current of the current transformers matches the rated current of the device, otherwise the device will incorrectly calculate primary data. At addresses 217 Ignd-CT PRIM and 218 Ignd-CT SEC, information is entered regarding the primary and secondary ampere rating of the current transformers. In case of normal connection (starpoint current connected to IN-transformer) 217 Ignd-CT PRIM and 204 CT PRIMARY must be set to the same value. If the device features a sensitive ground current input, address 218 Ignd-CT SEC is set to 1 A. In this case setting cannot be changed. Nominal Values of Voltage Transformers (VTs) At addresses 202 Vnom PRIMARY and 203 Vnom SECONDARY, information is entered regarding the primary nominal voltage and secondary nominal voltage (phase-tophase) of the connected voltage transformers. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 46 2 Functions Transformation Ratio of Voltage Transformers (VTs) In address 206 Vph / Vdelta the adjustment factor between phase voltage and displacement voltage is communicated to the device. This information is relevant for the detection of ground faults (in grounded systems and non-grounded systems), operational measured value VN and measured-quantity monitoring. If the voltage transformer set provides open delta windings, and if these windings are connected to the device, this must be specified accordingly in address 213 (see above margin heading "Voltage Connection"). Since the voltage transformer ratio is normally as follows: The factor Vph/VN (secondary voltage, address 206 Vph / Vdelta) has the relation to 3/ 3 = 3 = 1.73 which must be used if the VN voltage is connected. For other transformation ratios, i.e. the formation of the displacement voltage via an interconnected transformer set, the factor must be corrected accordingly. Please take into consideration that also the calculated secondary VN-voltage is divided by the value set in address 206 Vph / Vdelta. Thus, even if the VN-voltage is not connected, address 206 Vph / Vdelta has an impact on the secondary operational measured value VN. Trip and Close Command Duration (CB) Address 210 TMin TRIP CMD is used to set the minimum time the tripping contacts will remain closed. This setting applies to all protective functions that initiate tripping. Current Flow Monitoring (CB) Address 212 BkrClosed I MIN corresponds to the threshold value of the integrated current flow monitoring system. This parameter is used by several protection functions (e.g. voltage protection with current criterion, breaker failure protection, overload protection, restart inhibit for motors and CB maintenance). If the configured current value exceeds the setting, the circuit-breaker is considered closed. Address 211 TMax CLOSE CMD is used to set the maximum time the closing contacts will remain closed. This setting applies to the integrated reclosing function This setting must be long enough to allow the circuit breaker contacts to reliably engage. An excessive duration causes no problem since the closing command is interrupted in the event another trip is initiated by a protective function. The threshold value setting applies to all three phases, and must take into consideration all used protective functions. With regard to breaker failure protection, the threshold value must be set at a level below the minimum fault current for which breaker failure protection must operate. A setting of 10% below the minimum fault current for which breaker failure protection must operate is recommended. The pickup value should not be set too low, otherwise, the danger exists that transients in the current transformer secondary circuit could lead to extended drop out times if extremely high currents are switched off. When using the device for motor protection, overload protection and restart inhibit, the protective relay can distinguish between a running motor and a stopped motor, as well as take into account the different motor cool-down behaviour. For this application, the set value must be lower than the minimum no-load current of the motor. Circuit Breaker Maintenance (CBM) 47 Parameters 260 to 267 are assigned to CB maintenance. The parameters and the different procedures are explained in the setting notes of this function (see Section 2.23.3). SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.1 General 2.1.3.3 Settings Addresses which have an appended "A" can only be changed with DIGSI, under "Display Additional Settings". The table indicates region-specific default settings. Column C (configuration) indicates the corresponding secondary nominal current of the current transformer. Addr. Parameter C Setting Options Default Setting Comments 201 CT Starpoint towards Line towards Busbar towards Line CT Starpoint 202 Vnom PRIMARY 0.10 .. 800.00 kV 12.00 kV Rated Primary Voltage 203 Vnom SECONDARY 100 .. 225 V 100 V Rated Secondary Voltage (L-L) 204 CT PRIMARY 10 .. 50000 A 100 A CT Rated Primary Current 205 CT SECONDARY 1A 5A 1A CT Rated Secondary Current 206A Vph / Vdelta 1.00 .. 3.00 1.73 Matching ratio Phase-VT To Open-Delta-VT 209 PHASE SEQ. ABC ACB ABC Phase Sequence 210A TMin TRIP CMD 0.01 .. 32.00 sec 0.15 sec Minimum TRIP Command Duration 211A TMax CLOSE CMD 0.01 .. 32.00 sec 1.00 sec Maximum Close Command Duration 212 BkrClosed I MIN 1A 0.04 .. 1.00 A 0.04 A 5A 0.20 .. 5.00 A 0.20 A Closed Breaker Min. Current Threshold 213 VT Connect. 3ph Van, Vbn, Vcn Vab, Vbc, VGnd Van,Vbn,Vcn,VGn Van,Vbn,Vcn,VSy Van, Vbn, Vcn VT Connection, threephase 214 Rated Frequency 50 Hz 60 Hz 50 Hz Rated Frequency 215 Distance Unit km Miles km Distance measurement unit 217 Ignd-CT PRIM 1 .. 50000 A 60 A Ignd-CT rated primary current 218 Ignd-CT SEC 1A 5A 1A Ignd-CT rated secondary current 235A ATEX100 NO YES NO Storage of th. Replicas w/o Power Supply 240 VT Connect. 1ph NO Van Vbn Vcn Vab Vbc Vca NO VT Connection, singlephase 250A 50/51 2-ph prot ON OFF OFF 50, 51 Time Overcurrent with 2ph. prot. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 48 2 Functions Addr. Parameter C Setting Options Default Setting Comments 260 Ir-52 10 .. 50000 A 125 A Rated Normal Current (52 Breaker) 261 OP.CYCLES AT Ir 100 .. 1000000 10000 Switching Cycles at Rated Normal Current 262 Isc-52 10 .. 100000 A 25000 A Rated Short-Circuit Breaking Current 263 OP.CYCLES Isc 1 .. 1000 50 Switch. Cycles at Rated Short-Cir. Curr. 264 Ix EXPONENT 1.0 .. 3.0 2.0 Exponent for the IxMethod 265 Cmd.via control (Setting options depend on configuration) None 52 B.Wear: Open Cmd. via Control Device 266 T 52 BREAKTIME 1 .. 600 ms 80 ms Breaktime (52 Breaker) 267 T 52 OPENING 1 .. 500 ms 65 ms Opening Time (52 Breaker) 276 TEMP. UNIT Celsius Fahrenheit Celsius Unit of temperature measurement 613A Gnd O/Cprot. w. Ignd (measured) 3I0 (calcul.) Ignd (measured) Ground Overcurrent protection with 614A OP. QUANTITY 59 Vphph V2 Vphph Opera. Quantity for 59 Overvolt. Prot. 615A OP. QUANTITY 27 V1 Vphph V1 Opera. Quantity for 27 Undervolt. Prot. 2.1.3.4 No. 5145 Information List Information >Reverse Rot. Type of Information SP Comments >Reverse Phase Rotation 5147 Rotation ABC OUT Phase rotation ABC 5148 Rotation ACB OUT Phase rotation ACB 49 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.1 General 2.1.4 Oscillographic Fault Records The Multi-Functional Protection with Control 7SJ62/63/64 is equipped with a fault record memory. The instantaneous values of the measured quantities iA, iB, iC, iN or iNS and vA, vB, vC, vN or 3 * v0 and vSYN (only 7SJ64) (voltages in accordance with connection) are sampled at intervals of 1.25 ms (for 50Hz) and stored in a circulating buffer (16 samples per cycle). For a fault, the data are stored for an adjustable period of time, but not more than 5 seconds (up to 20 seconds for 7SJ64). Up to 8 fault records can be recorded in this buffer. The fault record memory is automatically updated with every new fault, so no acknowledgment for previously recorded faults is required. The fault record buffer can also be started with protection pickup, via binary input and serial port. 2.1.4.1 Description The data can be retrieved via the serial interfaces by means of a personal computer and evaluated with the protection data processing program DIGSI and the graphic analysis software SIGRA 4. The latter graphically represents the data recorded during the system fault and also calculates additional information from the measured values. Currents and voltages can be presented as desired as primary or secondary values. Signals are additionally recorded as binary tracks (marks) e.g. "pickup", "trip". If the device has a serial system interface, the fault recording data can be passed on to a central device via this interface. The evaluation of the data is done by applicable programs in the central device. Currents and voltages are referred to their maximum values, scaled to their rated values and prepared for graphic representation. Binary signal traces (marks) of particular events e.g. "fault detection", "tripping" are also represented. In the event of transfer to a central device, the request for data transfer can be executed automatically and can be selected to take place after each fault detection by the protection, or only after a trip. 2.1.4.2 Setting Notes Configuration Fault recording (waveform capture) will only take place if address 104 OSC. FAULT REC. is set to Enabled. Other settings pertaining to fault recording (waveform capture) are found under the Osc. Fault Rec. submenu of the SETTINGS menu. It has to be distinguish for the fault recording between the trigger and the recording criterion (address 401 WAVEFORMTRIGGER). Normally the trigger is the pickup of a protective element, i.e. when a protective element picks up the time is 0. The criterion for saving may be both the device pickup (Save w. Pickup) or the device trip (Save w. TRIP). A trip command issued by the device can also be used as trigger (Start w. TRIP); in this case it is also the recording criterion. A fault event starts with the pickup by any protective function and ends when the last pickup of a protective function has dropped out. Usually this is also the extent of a fault recording (address 402 WAVEFORM DATA = Fault event). If automatic reclosures are performed, the entire network fault -- or with more automatic reclosures -- can be recorded up to a final clearing (address 402 WAVEFORM DATA = Pow.Sys.Flt.). This facilitates the representation of the entire system fault history, but also consumes storage capacity during the auto-reclosure dead time(s). SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 50 2 Functions The actual storage time encompasses the pre-fault time PRE. TRIG. TIME (address 404) ahead of the reference instant, the normal recording time and the post-fault time POST REC. TIME (address 405) after the storage criterion has reset. The maximum length of a fault record MAX. LENGTH is entered in Address 403. The saving of each fault record must not exceed five seconds. A total of 8 records can be saved. However, the total length of time of all fault records in the buffer may not exceed 5 seconds. An oscillographic record can be triggered by a change in status of a binary input, or through the operating interface via PC. Storage is then triggered dynamically. The length of the fault recording is set in address 406 BinIn CAPT.TIME (maximum length however is MAX. LENGTH, address 403). Pre-fault and post-fault times will be included. If the binary input time is set for , then the length of the record equals the time that the binary input is activated (static), or the MAX. LENGTH setting in address 403, whichever is shorter. 2.1.4.3 Addr. Settings Parameter Setting Options Default Setting Comments 401 WAVEFORMTRIGGE R Save w. Pickup Save w. TRIP Start w. TRIP Save w. Pickup Waveform Capture 402 WAVEFORM DATA Fault event Pow.Sys.Flt. Fault event Scope of Waveform Data 403 MAX. LENGTH 0.30 .. 5.00 sec 2.00 sec Max. length of a Waveform Capture Record 404 PRE. TRIG. TIME 0.05 .. 0.50 sec 0.25 sec Captured Waveform Prior to Trigger 405 POST REC. TIME 0.05 .. 0.50 sec 0.10 sec Captured Waveform after Event 406 BinIn CAPT.TIME 0.10 .. 5.00 sec; 0.50 sec Capture Time via Binary Input 2.1.4.4 Information List No. - Information Type of Information Comments FltRecSta IntSP Fault Recording Start 4 >Trig.Wave.Cap. SP >Trigger Waveform Capture 203 Wave. deleted OUT_Ev Waveform data deleted 30053 Fault rec. run. OUT Fault recording is running 51 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.1 General 2.1.5 Settings Groups Four independent setting groups can be created for establishing the device's function settings. Applications 2.1.5.1 * Setting groups enables the user to save the corresponding settings for each application so that they can be quickly called when required. All setting groups are stored in the relay. Only one setting group may be active at a given time. Description Changing Setting Groups During operation the user can switch back and fourth between setting groups locally, via the operator panel, binary inputs (if so configured), the service interface using a personal computer, or via the system interface. For reasons of safety it is not possible to change between setting groups during a power system fault. A setting group includes the setting values for all functions that have been selected as Enabled during configuration (see Section 2.1.1.2). In 7SJ62/63/64 devices, four independent setting groups (A to D) are available. Whereas setting values may vary, the selected functions of each setting group remain the same. 2.1.5.2 General Setting Notes If multiple setting groups are not required, group A is the default selection. Then, the rest of this section is not applicable. If multiple setting groups are desired, address Grp Chge OPTION must be set to Enabled (address 103). For the setting of the function parameters, you configure each of the required setting groups A to D, one after the other. A maximum of 4 is possible. Please refer to the SIPROTEC 4 System Description, to learn how to copy setting groups or reset them to their status at delivery and also what you have to do to change from one setting group to another. Subsection 3.1 of this manual tells you how to change between several setting groups externally via binary inputs. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 52 2 Functions 2.1.5.3 Addr. 302 2.1.5.4 Settings Parameter CHANGE Setting Options Group A Group B Group C Group D Binary Input Protocol Default Setting Group A Comments Change to Another Setting Group Information List No. Information Comments Type of Information - Group A IntSP Group A - Group B IntSP Group B - Group C IntSP Group C - Group D IntSP Group D 7 >Set Group Bit0 SP >Setting Group Select Bit 0 8 >Set Group Bit1 SP >Setting Group Select Bit 1 53 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.1 General 2.1.6 Power System Data 2 2.1.6.1 Description The general protection data (P.System Data 2) includes settings associated with all functions rather than a specific protection or monitoring function. In contrast to the P.System Data 1 as discussed before, they can be changed over with the setting groups. Applications If the primary reference voltage and the primary reference current of the protected object are set, the device is able to calculate and output the percentage operational measured values. For protection of motors the motor starting detection represents an important feature. Exceeding a configured current value serves as a criterion. 2.1.6.2 Setting Notes Definition of Nominal Rated Values At addresses 1101 FullScaleVolt. and 1102 FullScaleCurr., the primary reference voltage (phase-to-phase) and reference current (phase) of the protected equipment is entered (e.g. motors). If these reference values match the primary VT and CT rating, they correspond to the settings in address 202and 204 (Subsection 2.1.3.2). They are generally used to show values referenced to full scale. Ground Impedance Ratios (only for Fault Location) The ground impedance ratio is only relevant for line fault location. At address 1103, resistance ratio RG/RL Ratio is entered, and at address 1104, the reactance ratio XG/XL Ratio is entered. They are calculated separately, and do not correspond to the real and imaginary components of Z0/Z1. Therefore, no complex calculations are necessary! The ratios are obtained from system data using the following formula: Where R0 - Zero sequence resistance of the line X0 - Zero sequence reactance of the line R1 - Positive sequence resistance of the line X1 - Positive sequence reactance of the line These values may either apply to the entire line length or be based on a per unit of line length, as the quotients are independent of length. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 54 2 Functions Calculation Example: 20 kV overhead line 120 mm2 with the following data: R1/s = 0.39 /mile Positive sequence resistance X1/s = 0.58 /mile Positive sequence reactance R0/s = 1.42 /mile Zero sequence resistance X0/s = 2.03 /mile Zero sequence reactance For ground impedance ratios, the following result: These values are set at addresses 1103 and 1104 respectively. Reactance Setting (only for Fault Location) The reactance setting must only be entered if using the line fault location function. The reactance setting enables the protective relay to indicate the fault location in terms of distance. The reactance value X' is entered as a value x' at address 1105 in per mile if set to distance unit Miles (address 215, see Section 2.1.3.2 "Distance Unit") , or at address 1106 in per kilometer if set to distance unit km. If the setting of address 215 is modified after entry of a reactance value at address 1105 or 1106, the reactance value must be modified and reentered accordingly. When using the PC and DIGSI for configuration, these values can also be entered as primary values. The following conversion to secondary values is then not relevant. For calculation of primary values in terms of secondary values the following applies in general: Likewise, the following goes for the reactance setting of a line: with 55 NCTR -- Current transformer ratio NVTR -- Voltage transformer ratio SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.1 General Calculation Example: In the following, the same line as used in the example for ground impedance ratios (above) and additional data on the voltage transformers will be used: Current transformer 500 A / 5 A Voltage transformer 20 kV / 0.1 kV The secondary reactance value is calculated as follows: Recognition of Running Condition (only for motors) When the configured current value at Address 1107 I MOTOR START is exceeded, this will be interpreted as motor starting. This parameter is used by the start-up time monitoring and overload protection functions. For this setting the following should be considered: * A setting must be selected that is lower than the actual motor start-up current under all load and voltage conditions. * During motor start-up the thermal profile of the overload protection is "frozen" i.e., kept at constant level. This threshold should not be set unnecessarily low since it limits the operating range of the overload protection for high currents during operation. Inversion of Measured Power Values / Metered Values The directional values (power, power factor, work and related min., max. and mean values), calculated in the operational measured values, are usually defined with positive direction towards the protected object. This requires that the connection polarity for the entire device was configured accordingly in the P.System Data 1 (compare also "Polarity of Current Transformers", address 201). It is also possible to apply different settings to the "forward" direction for the protective functions and the positive direction for the power etc., e.g. to have the active power supply (from the line to the busbar) displayed positively. To do so, set address 1108 P,Q sign to reversed. If the setting is not reversed (default), the positive direction for the power etc. corresponds to the "forward" direction for the protective functions. Chapter 4 provides a detailed list of the values in question. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 56 2 Functions 2.1.6.3 Settings The table indicates region-specific default settings. Column C (configuration) indicates the corresponding secondary nominal current of the current transformer. Addr. Parameter C Setting Options Default Setting Comments 1101 FullScaleVolt. 0.10 .. 800.00 kV 12.00 kV Measurem:FullScaleVoltage(Equipm.rating) 1102 FullScaleCurr. 10 .. 50000 A 100 A Measurem:FullScaleCurrent(Equipm.rating) 1103 RG/RL Ratio -0.33 .. 7.00 1.00 RG/RL - Ratio of Gnd to Line Resistance 1104 XG/XL Ratio -0.33 .. 7.00 1.00 XG/XL - Ratio of Gnd to Line Reactance 1105 x' 1A 0.0050 .. 15.0000 /mi 0.2420 /mi 5A 0.0010 .. 3.0000 /mi 0.0484 /mi x' - Line Reactance per length unit 1A 0.0050 .. 9.5000 /km 0.1500 /km 5A 0.0010 .. 1.9000 /km 0.0300 /km 1A 0.40 .. 10.00 A 2.50 A 5A 2.00 .. 50.00 A 12.50 A not reversed reversed not reversed 1106 1107 1108 2.1.6.4 x' I MOTOR START P,Q sign x' - Line Reactance per length unit Motor Start Current (Block 49, Start 48) P,Q operational measured values sign Information List No. Information Type of Information Comments 126 ProtON/OFF IntSP Protection ON/OFF (via system port) 356 >Manual Close SP >Manual close signal 501 Relay PICKUP OUT Relay PICKUP 511 Relay TRIP OUT Relay GENERAL TRIP command 533 Ia = VI Primary fault current Ia 534 Ib = VI Primary fault current Ib 535 Ic = VI Primary fault current Ic 561 Man.Clos.Detect OUT Manual close signal detected 2720 >Enable ANSI#-2 SP >Enable 50/67-(N)-2 (override 79 blk) 4601 >52-a SP >52-a contact (OPEN, if bkr is open) 4602 >52-b SP >52-b contact (OPEN, if bkr is closed) 16019 >52 Wear start SP >52 Breaker Wear Start Criteria 16020 52 WearSet.fail OUT 52 Wear blocked by Time Setting Failure 16027 52WL.blk I PErr OUT 52 Breaker Wear Logic blk Ir-CB>=Isc-CB 16028 52WL.blk n PErr OUT 52 Breaker W.Log.blk SwCyc.Isc>=SwCyc.Ir 57 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.1 General 2.1.7 EN100-Module 2.1.7.1 Functional Description The EN100-Module enables integration of the 7SJ62/63/64 in 100-MBit communication networks in control and automation systems with the protocols according to IEC 61850 standard. This standard permits continuous communication of the devices without gateways and protocol converters. Even when installed in heterogeneous environments, SIPROTEC 4 relays therefore provide for open and interoperable operation. Besides control system integration, this interface enables DIGSI-communication and inter-relay communication via GOOSE. 2.1.7.2 Setting Notes Interface Selection 2.1.7.3 No special settings are required for operating the Ethernet system interface module (IEC 1850, EN100-Module). If the ordered version of the device is equipped with such a module, it is automatically allocated to the interface available for it, namely Port B. Information List No. Information Type of Information Comments 009.0100 Failure Modul IntSP Failure EN100 Modul 009.0101 Fail Ch1 IntSP Failure EN100 Link Channel 1 (Ch1) 009.0102 Fail Ch2 IntSP Failure EN100 Link Channel 2 (Ch2) SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 58 2 Functions 2.2 Overcurrent Protection 50, 51, 50N, 51N General time overcurrent protection is the main protective function of the 7SJ62/63/64 relay. Each phase current and the ground current is provided with three elements. All elements are independent of each other and can be combined in any way. If it is desired in isolated or resonant-grounded systems that three-phase devices should work together with two-phase protection equipment, the time-overcurrent protection can be configured such that it allows two-phase operation besides three-phase mode (see Section 2.1.3.2). High-current element 50-2 and overcurrent element 50-1 always operate with definite tripping time, the third element 51, operates always with inverse tripping time. Applications 2.2.1 * The non-directional time overcurrent protection is suited for networks that are radial and supplied from a single source or open looped networks or for backup protection of differential protective schemes of all types of lines, transformers, generators, motors, and busbars. General Depending on parameter 613 Gnd O/Cprot. w. the overcurrent protection for the ground current can either operate with measured values IN or with the quantities 3I0 calculated from the three phase currents. Devices featuring a sensitive ground current input, however, generally use the calculated quantity 3I0. All overcurrent element enabled in the device may be blocked via the automatic reclosure function (depending on the cycle) or via an external signal to the binary inputs of the device. Removal of blocking during pickup will restart time delays. The Manual Close signal is an exception. If a circuit breaker is manually closed onto a fault current, it can be re-opened immediately. For overcurrent or high-set element the delay may be bypassed via a Manual Close pulse, thus resulting in high speed tripping. This pulse is extended up to at least 300 ms. The automatic reclosure function 79 may also initiate immediate tripping for the overcurrent and high-set elements depending on the cycle. Pickup of the 50Ns elements can be stabilized by setting the dropout times. This protection comes into use in systems where intermittent faults occur. Combined with electromechanical relays, it allows different dropout responses to be adjusted and a time grading of digital and electromechanical relays to be implemented. Pickup and delay settings may be quickly adapted to system requirements via dynamic setting swapping (see Section 2.4). Tripping by the 50-1, 51 elements (in phases), 50N-1 and 51N elements (in ground path) may be blocked for inrush conditions by utilizing the inrush restraint feature. 59 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.2 Overcurrent Protection 50, 51, 50N, 51N The following table gives an overview of the interconnection to other functions of 7SJ62/63/64. Table 2-1 Interconnection to other functions Time Overcurrent Connection to AutoElements matic Reclosing 2.2.2 Manual CLOSE Dynamic Cold Inrush Restraint Load Pickup 50-1 * * * * 50-2 * * * 51 * * * * 50N-1 * * * * 50N-2 * * * 51N * * * * Definite High-Current Elements 50-2, 50N-2 Phase and ground currents are compared separately with the pickup values of the high-set elements 50-2 and 50N-2. If the respective pickup value is exceeded this is signalled. After the user-defined time delays 50-2 DELAY or 50N-2 DELAY have elapsed, trip signals are issued. Signals are available for each element. The dropout value is roughly equal to 95% of the pickup value for currents greater than > 0.3 INom. Pickup can be stabilized by setting dropout times 1215 50 T DROP-OUT or 1315 50N T DROP-OUT. This time is started and maintains the pickup condition if the current falls below the threshold. The function thus does not drop out instantaneously. The trip delay time 50-2 DELAY or 50N-2 DELAY continues in the meantime. After the dropout delay time has elapsed, the pickup is reported OFF and the trip delay time is reset unless the threshold 50-2 PICKUP or 50N-2 PICKUP has been violated again. If the threshold is exceeded again while the dropout delay time is still running, it will be cancelled. The trip delay time 50-2 DELAY or 50N-2 DELAY continues in the meantime. If the threshold is still exceeded after the time has elapsed, a trip will be initiated immediately. If the threshold violation then no longer exists, there will be no response. If the threshold is violated again after the trip command delay time has elapsed and while the dropout delay time is still running, a trip will be initiated at once. These elements can be blocked by the automatic reclosure feature (AR). SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 60 2 Functions The following figures show the logic diagrams for the high-current elements 50-2 and 50N-2. Figure 2-3 Logic diagram of the 50-2 high-current element for phases If parameter MANUAL CLOSE is set to 50-2 instant. and manual close detection applies, the trip is initiated as soon as the pickup conditions arrive, even if the element is blocked via binary input. The same applies to 79AR 50-2 instantaneous. 61 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.2 Overcurrent Protection 50, 51, 50N, 51N Figure 2-4 Logic diagram of the 50N-2 high-current element for ground If parameter MANUAL CLOSE is set to 50N-2 instant. and manual close detection applies, the trip is initiated as soon as the pickup conditions arrive, even if the element is blocked via binary input. The same applies to 79AR 50N-2 instantaneous. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 62 2 Functions 2.2.3 Definite Overcurrent Elements 50-1, 50N-1 Each phase and ground current is compared separately with the setting values of the 50-1 and 50N-1 relay elements and is signalled separately when exceeded. If the inrush restraint feature (see below) is applied, either the normal pickup signals or the corresponding inrush signals are output as long as inrush current is detected. After user-configured time delays 50-1 DELAY and 50N-1 DELAY have elapsed, a trip signal is issued if no inrush current is detected or inrush restraint is disabled. If the inrush restraint feature is enabled, and an inrush condition exists, no tripping takes place, but a message is recorded and displayed indicating when the overcurrent element time delay elapses. Tripping signals and signals on the expiration of time delay are available separately for each element. The dropout value is roughly equal to 95% of the pickup value for currents greater than > 0.3 INom. Pickups can be stabilized by setting dropout times 1215 50 T DROP-OUT or 1315 50N T DROP-OUT. This time is started and maintains the pickup condition if the current falls below the threshold. The function thus does not drop out instantaneously. The trip delay time 50-1 DELAY or 50N-1 DELAY continues in the meantime. After the dropout delay time has elapsed, the pickup is reported OFF and the trip delay time is reset unless the threshold 50-1 PICKUP or 50N-1 PICKUP has been violated again. If the threshold is violated again while the dropout delay time is still running, it will be cancelled. The trip delay time 50-1 DELAY or 50N-1 DELAY continues in the meantime. If the threshold is still exceeded after the time has elapsed, a trip will be initiated immediately. If the threshold violation then no longer exists, there will be no response. If the threshold is violated again after the trip command delay time has elapsed and while the dropout delay time is still running, a trip will be initiated at once. Pickup stabilization of the overcurrent elements 50-1 or 50N-1 by means of settable dropout time is deactivated if an inrush pickup is present since an inrush does not represent an intermittent fault. These elements can be blocked by the automatic reclosure feature (AR). 63 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.2 Overcurrent Protection 50, 51, 50N, 51N The following figures show the logic diagrams for the current elements 50-1 and 50N1. Figure 2-5 Logic diagram of the 50-1 current element for phases The dropout delay only operates if no inrush was detected. An incoming inrush will reset a running dropout delay time. If parameter MANUAL CLOSE is set to 50 -1 instant. and manual close detection applies, the trip is initiated as soon as the pickup conditions arrive, even if the element is blocked via binary input. The same applies to 79AR 50-1 instantaneous. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 64 2 Functions Figure 2-6 Logic of the dropout delay for 50-1 phase current element Figure 2-7 Logic diagram of the 50N-1 current element for ground If parameter MANUAL CLOSE is set to 50N-1 instant. and manual close detection applies, the trip is initiated as soon as the pickup conditions arrive, even if the element is blocked via binary input. The same applies to 79AR 50N-1 instantaneous. The pickup values of each element 50-1, 50-2 for the phase currents and 50N-1, 50N2 for the ground current and the valid delay times for each element can be set individually. The dropout delay only operates if no inrush was detected. An arriving inrush will reset an already running dropout delay time. 65 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.2 Overcurrent Protection 50, 51, 50N, 51N Figure 2-8 2.2.4 Logic of the dropout delay for 50N-1 ground current element Inverse Time Overcurrent Elements 51, 51N Inverse time elements are dependent on the variant ordered. They operate with an inverse time characteristic either according to the IEC- or the ANSI-standard or with a user-defined characteristic. The characteristics and associated formulas are given in the Technical Data. If inverse time characteristics have been configured, definite time elements 50-2 and 50-1 are also enabled (see Sections "Definite Time High-Set Elements 50-2, 50N-2" and "Definite Time Overcurrent Elements 50-1, 50N-1"). Pickup Behaviour Each phase and ground current is separately compared with the pickup values of the inverse time overcurrent protection element 51 and 51N. If a current exceeds 1.1 times the setting value, the corresponding element picks up and is signalled individually. If the inrush restraint feature is applied, either the normal pickup signals or the corresponding inrush signals are output as long as inrush current is detected. Pickup of a relay element is based on the rms value of the fundamental harmonic. When the 51 element picks up, the time delay of the trip signal is calculated using an integrated measurement process. The calculated time delay is dependent on the actual fault current flowing and the selected tripping characteristics. Once the time delay elapses, a trip signal is issued assuming that no inrush current is detected or inrush restraint is disabled. If the inrush restraint feature is enabled and an inrush condition exists, no tripping takes place, but a message is recorded and displayed indicating when the overcurrent element time delay elapses. These elements can be blocked by the automatic reclosure feature (79). For ground current element 51N the characteristic may be selected independently of the characteristic used for phase currents. Pickup values of elements 51 (phases) and 51N (ground current) and the associated time multipliers may be individually set. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 66 2 Functions The following two figures show the logic diagrams for the 51 and 51N protection. Figure 2-9 Logic diagram of the 51 current element for phases If parameter MANUAL CLOSE is set to 51 instant. and manual close detection applies, the trip is initiated as soon as the pickup conditions arrives, even if the element is blocked via binary input. The same applies to 79AR 51 instantaneous. 67 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.2 Overcurrent Protection 50, 51, 50N, 51N Figure 2-10 Logic diagram of the 51N current element for ground If parameter MANUAL CLOSE is set to 51N instant. and manual close detection applies, the trip is initiated as soon as the pickup conditions arrive, even if the element is blocked via binary input. The same applies to 79AR 51N instantaneous. Dropout Behaviour When using an ANSI or IEC curve select whether the dropout of an element is to occur instantaneously after the threshold has been undershot or whether dropout is to be performed by means of the disk emulation. "Instantaneously" means that pickup drops out when the pickup value of approx. 95 % is undershot. For a new pickup the time counter starts at zero. The disk emulation evokes a dropout process (time counter is decrementing) which begins after de-energization. This process corresponds to the reset of a Ferraris-disk (explaining its denomination "disk emulation"). In case several faults occur in succession the "history" is taken into consideration due to the inertia of the Ferraris-disk and the time response is adapted. Reset begins as soon as 90% of the setting value is undershot, in accordance to the dropout curve of the selected characteristic. In the range between the dropout value (95% of the pickup value) and 90% of the setting value, the incrementing and the decrementing processes are in idle state. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 68 2 Functions Disk emulation offers advantages when the overcurrent relay elements must be coordinated with conventional electromechanical overcurrent relays located toward the source. User Defined Curves When user defined characteristics are utilized, the tripping curve may be defined point by point. Up to 20 pairs of values (current, time) may be entered. The device then approximates the characteristic, using linear interpolation. The dropout curve may be user-defined as well. See dropout for ANSI and IEC curves in the function description. If no user-defined dropout curve is required, the element drops out as soon as the respective current falls below approx. 95% of the set pickup value. When a new pickup is evoked, the timer starts again at zero. 2.2.5 Dynamic Cold Load Pickup Function It may be necessary to dynamically increase the pickup values if, during starting, certain elements of the system show an increased power consumption after a long period of zero voltage (e.g. air-conditioning systems, heating installations, motors). Thus, a general raise of pickup thresholds can be avoided taking such starting conditions into consideration. This dynamic pickup value changeover is common to all overcurrent elements and is described in Section 2.4. The alternative pickup values can be set individually for each element of the time overcurrent protection. 2.2.6 Inrush Restraint When the multi-functional protective relay with local control 7SJ62/63/64 is installed, for instance, to protect a power transformer, large magnetizing inrush currents will flow when the transformer is energized. These inrush currents may be several times the nominal transformer current, and, depending on the transformer size and design, may last from several milliseconds to several seconds. Although pickup of the relay elements is based only on the fundamental harmonic component of the measured currents, false device pickup due to inrush is still a potential problem since, depending on the transformer size and design, the inrush current also comprises a large component of the fundamental. The 7SJ62/63/64 features an integrated inrush restraint function. It prevents the "normal" pickup of the 50-1 or 51 elements (not 50-2) in the phases and the ground path of the non-directional and directional time-overcurrent protection. The same is true for the alternative pickup thresholds of the dynamic cold load pickup function. After detection of inrush currents above a pickup value special inrush signals are generated. These signals also initiate fault annunciations and start the associated trip delay time. If inrush conditions are still present after the tripping time delay has elapsed, a corresponding message (....Timeout.") is output, but the overcurrent tripping is blocked (see also logic diagrams of time overcurrent elements, Figures 2-5 to 2-10). Inrush current contains a relatively large second harmonic component (twice the nominal frequency) which is nearly absent during a fault current. The inrush restraint is based on the evaluation of the 2nd harmonic present in the inrush current. For frequency analysis, digital filters are used to conduct a Fourier analysis of all three phase currents and the ground current. 69 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.2 Overcurrent Protection 50, 51, 50N, 51N Inrush current is recognized, if the following conditions are fulfilled at the same time: * the harmonic content is larger than the setting value 2202 2nd HARMONIC; * the currents do not exceed an upper limit value 2205 I Max; * an exceeding of a threshold value via an inrush restraint of the blocked element takes place. In this case an inrush in the affected phase is recognized (annunciations 1840 to 1842 and 7558 InRush Gnd Det", see figure 2-11) and its blocking being carried out. Since quantitative analysis of the harmonic components cannot be completed until a full AC cycle has been measured, pickup will generally be blocked by then. Therefore, assuming the inrush restraint feature is enabled, a pickup message will be delayed by a full AC cycle if no closing process is present. On the other hand, trip delay times of the time overcurrent protection feature are started immediately even with the inrush restraint being enabled. Time delays continue running with inrush currents present. If inrush blocking drops out after the time delay has elapsed, tripping will occur immediately. Therefore, utilization of the inrush restraint feature will not result in any additional tripping delays. If a relay element drops out during inrush blocking, the associated time delay will reset. Cross Blocking Since inrush restraint operates individually for each phase, protection is ideal when a transformer is energized onto a single-phase fault and inrush currents are detected on a different healthy phase. However, the protection feature can be configured to ensure that not only this phase element, but also the remaining elements (including ground) are blocked (the so-called CROSS BLOCK function, address 2203), if the permissible harmonic component of the current is exceeded for only one phase. Please take into consideration that inrush currents flowing in the ground path will not cross-block tripping by the phase elements. Cross blocking is reset if there is no more inrush in any phase. Furthermore, the cross blocking function may also be limited to a particular time interval (address 2204 CROSS BLK TIMER). After expiry of this time interval, the cross-blocking function will be disabled, even if inrush current is still present. The inrush restraint has an upper limit: Above this (via adjustable parameter 2205 I Max) current blocking is suppressed since a high-current fault is assumed in this case. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 70 2 Functions The following figure shows the inrush restraint influence on the time overcurrent elements including cross-blocking. Figure 2-11 71 Logic diagram for inrush restraint SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.2 Overcurrent Protection 50, 51, 50N, 51N 2.2.7 Pickup Logic and Tripping Logic The pickup annunciations of the individual phases (or ground) and the individual elements are combined with each other such that the phase information and the element that have picked up are issued. Table 2-2 Pickup annunciations of the time overcurrent protection Internal Annunciation Figure Output Annunciation FNo. 50-2 Ph A PU (Phase A, 2-3 pickup) 2-5 50-1 Ph A PU 2-9 51 Ph A PU 50/51 Ph A PU" 1762 50-2 Ph B PU 50-1 Ph B PU 51 Ph B PU 2-3 2-5 2-9 50/51 Ph B PU" 1763 50-2 Ph C PU 50-1 Ph C PU 51 Ph C PU 2-3 2-5 2-9 50/51 Ph C PU" 1764 50N-2 PU 50N-1 PU 51N PU 2-4 2-7 2-10 50N/51NPickedup" 1765 50-2 Ph A PU 50-2 Ph B PU 50-2 Ph C PU 50N-2 PU 2-3 2-3 2-3 2-4 50-2 picked up" 1800 50-1 Ph A PU 50-1 Ph B PU 50-1 Ph C PU 50N-1 PU 2-5 2-5 2-5 2-4 50-1 picked up" 1810 51 Ph A PU 51 Ph B PU 51 Ph C PU 51N PU 2-9 2-9 2-9 2-10 51 picked up" 1820 50(N)/51(N) PU" 1761 (All pickups) Also for the tripping signals the element is indicated which has initiated the tripping. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 72 2 Functions 2.2.8 Two-Phase Time Overcurrent Protection (non-directional only) Two-phase time overcurrent protection is used in isolated or resonant-grounded systems where interaction with existing two-phase protection equipment is required. Since an isolated or resonant-grounded system can still be operated with a ground fault in one phase, this protection function detects double ground faults with high ground fault currents. Only in the latter case, should a faulted feeder be shut down. Measuring in two phases is sufficient to this end. Only phases A and C are monitored in order to ensure selectivity of the protection in the network system. If 250 50/51 2-ph prot (settable in P.System Data 1) is set to ON, IB is not used for threshold comparison. If the fault is a simple ground fault in B, the element will not pick up. Only after pickup on A or C a double ground fault is assumed, causing the element to pick up and trip after the delay time has elapsed. Note With inrush recognition activated and inrush only on B, no crossblocking will take place in the other phases. On the other hand, if inrush with crossblocking is activated on A or C, B will also be blocked. 2.2.9 Busbar Protection by Use of Reverse Interlocking Application Example Each of the overcurrent elements can be blocked via binary inputs of the relay. A setting parameter determines whether the binary input operates in the normally open (i.e. actuated when energized) or the normally closed (i.e. actuated when de-energized) mode. This allows fast busbar protection to be applied in star systems or open ring systems by utilizing "reverse interlocking". This principle is often used, for example, in distribution systems, auxiliary systems of power plants, and the like, where a station supply transformer supplied from the transmission grid serves internal loads of the generation station via a medium voltage bus with multiple feeders (Figure 2-12). The reverse interlocking principle is based on the following: time overcurrent protection of the busbar feeder trips with a short time delay 50-2 DELAY independent of the grading times of the feeders, unless the pickup of the next load-side time overcurrent protection element blocks the bus protection (Figure 2-12). Always the protection element nearest to the fault will trip with the short time delay since this element cannot be blocked by a protection element located behind the fault. Time elements 50-1 DELAY or 51 TIME DIAL are still effective as backup element. Pickup signals output by the load-side protective relay are used as input message >BLOCK 50-2" via a binary input at the feeder-side protective relay. 73 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.2 Overcurrent Protection 50, 51, 50N, 51N Figure 2-12 Reverse interlocking protection scheme 2.2.10 Setting Notes General When selecting the time overcurrent protection in DIGSI a dialog box appears with several tabs, such as General, 50, 51, 50N, 51N and InrushRestraint for setting individual parameters. Depending on the functional scope specified during configuration of the protective functions in addresses 112 Charac. Phase and 113 Charac. Ground the number of tabs can vary. If address FCT 50/51 was set to Definite Time, or Charac. Ground to = Definite Time, then only the settings for the definite time elements are available. The selection of TOC IEC or TOC ANSI makes available additional inverse characteristics. The superimposed high-set elements 50-2 and 50N-2 are available in all these cases. Parameter 250 50/51 2-ph prot can also be set to activate two-phase overcurrent protection. At address 1201 FCT 50/51 the phase time-overcurrent protection and at address 1301 FCT 50N/51N the ground time-overcurrent protection may be switched ON or OFF. Pickup values, time delays, and characteristics for ground protection are set separately from the pickup values, time delays and characteristic curves associated with phase protection. Because of this, relay coordination for ground faults is independent of relay coordination for phase faults, and more sensitive settings can often be applied to directional ground protection. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 74 2 Functions 50-2 Element The pickup value of the relay element 50-2 is set at address 1202, the assigned time delay 50-2 DELAY at address 1203. This stage is often used for current grading in view of impedances such as transformers, motors or generators. It is specified such that it picks up for faults up to this impedance. Example: Transformer used to distribution bus supply with the following data: Rated Power of the Transformer SNomT = 16 MVA Transformer Impedance ZTX = 10 % Primary Nominal Voltage VNom1 = 110 kV Secondary Nominal Voltage VNom2 = 20 kV Vector Groups Dy 5 Starpoint Grounded Fault power on 110 kV-side 1 GVA Based on the data above, the following fault currents are calculated: 3-Phase High Side Fault Current at 110 kV = 5250 A 3-Phase Low Side Fault Current at 20 kV = 3928 A Current flowing on the High Side at 110 kV = 714 A The nominal current of the transformer is: INomT, 110 = 84 A (High side) INomT, 20 = 462 A (Low side) Current Transformer (High Side) 100 A / 1 A Current Transformer (Low Side) 500 A / 1 A Due to the following definition the following setting applies to the protection device: The 50-2 relay element must be set higher than the maximum fault current, which is detected during a low side fault on the high side. To reduce fault probability as much as possible even when fault power varies, the following setting is selected in primary values: I>>/INom = 10, i.e. I>> = 1000 A. Increased inrush currents, if the fundamental component exceeds the setting value, are rendered harmless by delay times (address 1203 50-2 DELAY). For motor protection, the 50-2 relay element must be set smaller than the smallest phase-to-phase fault current and larger than the largest motor starting current. Since the maximum appearing startup current is usually below 1.6 x the rated startup current (even with unfavorable conditions), the following setting is adequate for fault current stage 50-2: 1.6 x IStartup < 50-2 Pickup Manual Close" (no. 561). The internal "Manual close" signal remains active as long as the binary input signal >Manual Close" is active, but at lease for 300 ms (see the following logic diagram).To enable the device to react properly on occurrence of a fault in the phase elements after manual close, address 1213 MANUAL CLOSE has to be set accordingly. Accordingly, address 1313 MANUAL CLOSE is considered for the ground path address. Thus, the user determines for both elements, the phase and the ground element, what pickup value is active with what delay when the circuit breaker is closed manually. Figure 2-15 Manual close feature External Control Switch If the manual closing signal is not from a 7SJ62/63/64 relay, that is, neither sent via the built-in operator interface nor via a series interface, but, rather, directly from a control acknowledgment switch, this signal must be passed to a 7SJ62/63/64 binary input, and configured accordingly (>Manual Close"), so that the element selected for MANUAL CLOSE will be effective. Its alternative Inactive means that the element operates as configured even with manual close. Internal Control Function The manual closing information must be allocated via CFC (interlocking task-level) using the CMD_Information block, if the internal control function is used (see Figure 2-16). Figure 2-16 81 Example for manual close feature using the internal control function SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.2 Overcurrent Protection 50, 51, 50N, 51N Note For an interaction between the automatic reclosure (AR) and the control function, an extended CFC logic is necessary. See margin heading CLOSE command: Directly or via control" in the Setting Notes of the AR function (Section 2.14.6). Interaction with Automatic Reclosure Function (Phases) When reclosing occurs, it is desirable to have high speed protection against faults with 50-2. If the fault still exists after the first reclosure, elements 50-1 or 51 will be initiated with graded tripping times, that is, the 50-2 elements will be blocked. At address 1214 50-2 active, it can be specified whether (with 79 active) or not (Always) the 50-2 elements should be supervised by the status of an internal or external automatic reclosing device. Address with 79 active determines that the 50-2 elements will not operate unless automatic reclosing is not blocked. If not desired, then setting Always is selected having the effect that the 50-2 elements will always operate, as configured. The integrated automatic reclosing function of 7SJ62/63/64 also provides the option to individually determine for each time overcurrent element whether tripping or blocking is to be carried out instantaneously, unaffected by the AR with time delay (see Section 2.14). Interaction with Automatic Reclosing Function (ground) When reclosing is expected, it is desirable to have high speed protection against faults with 50N-2. If the fault still exists after the first reclosure, elements 50N-1 or 51N must operate with graded tripping times, that is, the 50N-2 elements will be blocked. At address 1314 50N-2 active, it can be specified whether (with 79 active) or not (Always) the 50N-2 elements should be supervised by the status of an internal or external automatic reclosing device. Address with 79 active determines that the 50N-2 elements will only operate when automatic reclosing is not blocked. If not desired, then setting Always is selected having the effect that the 50N-2 elements will always operate, as configured. The integrated automatic reclosing function of 7SJ62/63/64 also provides the option to individually determine for each time overcurrent element whether tripping or blocking is to be carried out instantaneously, unaffected by the AR with time delay (see Section 2.14). 2.2.11 Settings Addresses which have an appended "A" can only be changed with DIGSI, under "Display Additional Settings". The table indicates region-specific default settings. Column C (configuration) indicates the corresponding secondary nominal current of the current transformer. Addr. Parameter 1201 FCT 50/51 1202 50-2 PICKUP 1203 50-2 DELAY SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 C Setting Options Default Setting Comments ON OFF ON 50, 51 Phase Time Overcurrent 1A 0.10 .. 35.00 A; 2.00 A 50-2 Pickup 5A 0.50 .. 175.00 A; 10.00 A 0.00 .. 60.00 sec; 0.00 sec 50-2 Time Delay 82 2 Functions Addr. 1204 Parameter 50-1 PICKUP 1205 50-1 DELAY 1207 51 PICKUP C Setting Options Default Setting Comments 1A 0.10 .. 35.00 A; 1.00 A 5A 0.50 .. 175.00 A; 5.00 A 0.00 .. 60.00 sec; 0.50 sec 50-1 Time Delay 1A 0.10 .. 4.00 A 1.00 A 51 Pickup 5A 0.50 .. 20.00 A 5.00 A 50-1 Pickup 1208 51 TIME DIAL 0.05 .. 3.20 sec; 0.50 sec 51 Time Dial 1209 51 TIME DIAL 0.50 .. 15.00 ; 5.00 51 Time Dial 1210 51 Drop-out Instantaneous Disk Emulation Disk Emulation Drop-out characteristic 1211 51 IEC CURVE Normal Inverse Very Inverse Extremely Inv. Long Inverse Normal Inverse IEC Curve 1212 51 ANSI CURVE Very Inverse Inverse Short Inverse Long Inverse Moderately Inv. Extremely Inv. Definite Inv. Very Inverse ANSI Curve 1213A MANUAL CLOSE 50-2 instant. 50 -1 instant. 51 instant. Inactive 50-2 instant. Manual Close Mode 1214A 50-2 active Always with 79 active Always 50-2 active 1215A 50 T DROP-OUT 0.00 .. 60.00 sec 0.00 sec 50 Drop-Out Time Delay 1230 51/51N 1.00 .. 20.00 I/Ip; 0.01 .. 999.00 TD 51/51N 1231 MofPU Res T/Tp 0.05 .. 0.95 I/Ip; 0.01 .. 999.00 TD Multiple of Pickup <-> T/Tp 1301 FCT 50N/51N ON OFF ON 50N, 51N Ground Time Overcurrent 1302 50N-2 PICKUP 1A 0.05 .. 35.00 A; 0.50 A 50N-2 Pickup 5A 0.25 .. 175.00 A; 2.50 A 0.00 .. 60.00 sec; 0.10 sec 50N-2 Time Delay 1A 0.05 .. 35.00 A; 0.20 A 50N-1 Pickup 5A 0.25 .. 175.00 A; 1.00 A 0.00 .. 60.00 sec; 0.50 sec 50N-1 Time Delay 1A 0.05 .. 4.00 A 0.20 A 51N Pickup 5A 0.25 .. 20.00 A 1.00 A 1303 50N-2 DELAY 1304 50N-1 PICKUP 1305 50N-1 DELAY 1307 51N PICKUP 1308 51N TIME DIAL 0.05 .. 3.20 sec; 0.20 sec 51N Time Dial 1309 51N TIME DIAL 0.50 .. 15.00 ; 5.00 51N Time Dial 83 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.2 Overcurrent Protection 50, 51, 50N, 51N Addr. Parameter C Setting Options Default Setting Comments 1310 51N Drop-out Instantaneous Disk Emulation Disk Emulation Drop-Out Characteristic 1311 51N IEC CURVE Normal Inverse Very Inverse Extremely Inv. Long Inverse Normal Inverse IEC Curve 1312 51N ANSI CURVE Very Inverse Inverse Short Inverse Long Inverse Moderately Inv. Extremely Inv. Definite Inv. Very Inverse ANSI Curve 1313A MANUAL CLOSE 50N-2 instant. 50N-1 instant. 51N instant. Inactive 50N-2 instant. Manual Close Mode 1314A 50N-2 active Always With 79 Active Always 50N-2 active 1315A 50N T DROP-OUT 0.00 .. 60.00 sec 0.00 sec 50N Drop-Out Time Delay 1330 50N/51N 1.00 .. 20.00 I/Ip; 0.01 .. 999.00 TD 50N/51N 1331 MofPU Res T/TEp 0.05 .. 0.95 I/Ip; 0.01 .. 999.00 TD Multiple of Pickup <-> T/TEp 2201 INRUSH REST. OFF ON OFF Inrush Restraint 2202 2nd HARMONIC 10 .. 45 % 15 % 2nd. harmonic in % of fundamental 2203 CROSS BLOCK NO YES NO Cross Block 2204 CROSS BLK TIMER 0.00 .. 180.00 sec 0.00 sec Cross Block Time 2205 I Max 1A 0.30 .. 25.00 A 7.50 A 5A 1.50 .. 125.00 A 37.50 A Maximum Current for Inrush Restraint 2.2.12 Information List No. Information Type of Information Comments 1704 >BLK 50/51 SP >BLOCK 50/51 1714 >BLK 50N/51N SP >BLOCK 50N/51N 1721 >BLOCK 50-2 SP >BLOCK 50-2 1722 >BLOCK 50-1 SP >BLOCK 50-1 1723 >BLOCK 51 SP >BLOCK 51 1724 >BLOCK 50N-2 SP >BLOCK 50N-2 1725 >BLOCK 50N-1 SP >BLOCK 50N-1 1726 >BLOCK 51N SP >BLOCK 51N SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 84 2 Functions No. 1751 Information 50/51 PH OFF Type of Information OUT Comments 50/51 O/C switched OFF 1752 50/51 PH BLK OUT 50/51 O/C is BLOCKED 1753 50/51 PH ACT OUT 50/51 O/C is ACTIVE 1756 50N/51N OFF OUT 50N/51N is OFF 1757 50N/51N BLK OUT 50N/51N is BLOCKED 1758 50N/51N ACT OUT 50N/51N is ACTIVE 1761 50(N)/51(N) PU OUT 50(N)/51(N) O/C PICKUP 1762 50/51 Ph A PU OUT 50/51 Phase A picked up 1763 50/51 Ph B PU OUT 50/51 Phase B picked up 1764 50/51 Ph C PU OUT 50/51 Phase C picked up 1765 50N/51NPickedup OUT 50N/51N picked up 1791 50(N)/51(N)TRIP OUT 50(N)/51(N) TRIP 1800 50-2 picked up OUT 50-2 picked up 1804 50-2 TimeOut OUT 50-2 Time Out 1805 50-2 TRIP OUT 50-2 TRIP 1810 50-1 picked up OUT 50-1 picked up 1814 50-1 TimeOut OUT 50-1 Time Out 1815 50-1 TRIP OUT 50-1 TRIP 1820 51 picked up OUT 51 picked up 1824 51 Time Out OUT 51 Time Out 1825 51 TRIP OUT 51 TRIP 1831 50N-2 picked up OUT 50N-2 picked up 1832 50N-2 TimeOut OUT 50N-2 Time Out 1833 50N-2 TRIP OUT 50N-2 TRIP 1834 50N-1 picked up OUT 50N-1 picked up 1835 50N-1 TimeOut OUT 50N-1 Time Out 1836 50N-1 TRIP OUT 50N-1 TRIP 1837 51N picked up OUT 51N picked up 1838 51N TimeOut OUT 51N Time Out 1839 51N TRIP OUT 51N TRIP 1840 PhA InrushDet OUT Phase A inrush detection 1841 PhB InrushDet OUT Phase B inrush detection 1842 PhC InrushDet OUT Phase C inrush detection 1843 INRUSH X-BLK OUT Cross blk: PhX blocked PhY 1851 50-1 BLOCKED OUT 50-1 BLOCKED 1852 50-2 BLOCKED OUT 50-2 BLOCKED 1853 50N-1 BLOCKED OUT 50N-1 BLOCKED 1854 50N-2 BLOCKED OUT 50N-2 BLOCKED 1855 51 BLOCKED OUT 51 BLOCKED 1856 51N BLOCKED OUT 51N BLOCKED 1866 51 Disk Pickup OUT 51 Disk emulation Pickup 1867 51N Disk Pickup OUT 51N Disk emulation picked up 7551 50-1 InRushPU OUT 50-1 InRush picked up 7552 50N-1 InRushPU OUT 50N-1 InRush picked up 7553 51 InRushPU OUT 51 InRush picked up 7554 51N InRushPU OUT 51N InRush picked up 85 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.2 Overcurrent Protection 50, 51, 50N, 51N No. 7556 Information InRush OFF Type of Information OUT Comments InRush OFF 7557 InRush BLK OUT InRush BLOCKED 7558 InRush Gnd Det OUT InRush Ground detected 7559 67-1 InRushPU OUT 67-1 InRush picked up 7560 67N-1 InRushPU OUT 67N-1 InRush picked up 7561 67-TOC InRushPU OUT 67-TOC InRush picked up 7562 67N-TOCInRushPU OUT 67N-TOC InRush picked up 7563 >BLOCK InRush SP >BLOCK InRush 7564 Gnd InRush PU OUT Ground InRush picked up 7565 Ia InRush PU OUT Phase A InRush picked up 7566 Ib InRush PU OUT Phase B InRush picked up 7567 Ic InRush PU OUT Phase C InRush picked up SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 86 2 Functions 2.3 Directional Overcurrent Protection 67, 67N With directional time overcurrent protection the phase currents and the ground current are provided with three elements. All elements may be configured independently from each other and combined according to the user's requirements. High-current elements 67-2 and overcurrent element 67-1 always operate with definite tripping time, the third element 67-TOC, operates with inverse tripping time. Applications * The directional overcurrent protection allows the application of multifunctional protection devices 7SJ62/63/64 to systems where coordination protection depends on knowing both the magnitude of the fault current and the direction of energy flow to the fault location. * The time overcurrent protection (non-directional) described in Section 2.2 may operate as overlapping backup protection or may be disabled. Additionally, individual elements (e.g. 67-2 and/or 67N-2) may be interconnected with the directional overcurrent protection. * For parallel lines or transformers supplied from a single source only directional overcurrent protection allows selective fault detection. * For line sections supplied from two sources or in ring-operated lines the time overcurrent protection has to be supplemented by the directional criterion. 2.3.1 General For parallel lines or transformers supplied from a single source (Figure 2-17), the second feeder (II) is opened on occurrence of a fault in the first feeder (I) if tripping of the breaker in the parallel feeder is not prevented by a directional measuring element (at B). Therefore, where indicated with an arrow (Figure 2-17) directional overcurrent protection is applied. Be careful that the "Forward" direction of the protective element is in the direction of the line (or object to be protected). This is not necessarily identical with the direction of the normal load flow, as shown in Figure 2-17. 87 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.3 Directional Overcurrent Protection 67, 67N Figure 2-17 Overcurrent protection for parallel transformers For line sections supplied from two sources or in ring-operated lines the time overcurrent protection has to be supplemented by the directional criterion. Figure 2-18 shows a ring system where both energy sources are merged to one single source. Figure 2-18 Transmission lines with sources at each end Depending on the setting of parameter 613 Gnd O/Cprot. w., the ground current element can operate either with measured values IN or with the values 3I0 calculated from the three phase currents. Devices featuring a sensitive ground current input, however, use the calculated quantity 3I0. For each element the time can be blocked via binary input or automatic reclosure (cycle-dependent), thus suppressing the trip command. Removal of blocking during pickup will restart time delays. The Manual Close signal is an exception. If a circuit breaker is manually closed onto a fault, it can be re-opened immediately. For overcur- SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 88 2 Functions rent elements or high-set elements the delay may be bypassed via a Manual Close pulse, thus resulting in high-speed tripping. Furthermore, immediate tripping may be initiated in conjunction with the automatic reclosure function (cycle-dependent). Pickup stabilization for the 67/67N elements of the directional time overcurrent protection can be accomplished by means of settable dropout times. This protection comes into use in systems where intermittent faults occur. Combined with electromechanical relays, it allows different dropout responses to be adjusted and a time grading of digital and electromechanical relays to be implemented. Pickup and delay settings may be quickly adjusted to system requirements via dynamic setting swapping (see Section 2.4). Utilizing the inrush restraint feature tripping may be blocked by the 67-1, 67-TOC, 67N-1, and 67N-TOC elements in phases and ground path when inrush current is detected. The following table gives an overview of the interconnection to other functions of 7SJ62/63/64. Table 2-5 Interconnection to other functions Directional Time Connection to AutoOvercurrent Promatic Reclosing tection Elements 89 Manual CLOSE Dynamic Cold Inrush Restraint Load Pickup 67-1 * * * * 67-2 * * * 67-TOC * * * * 67N-1 * * * * 67N-2 * * * 67N-TOC * * * * SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.3 Directional Overcurrent Protection 67, 67N 2.3.2 Definite Time, Directional High-set Elements 67-2, 67N-2 Phase and ground current are compared separately with the pickup values 67-2 PICKUP and 67N-2 PICKUP of the respective relay elements. Currents above the setting values are signalled separately when fault direction is equal to the direction configured. After the user-defined time delays 67-2 DELAY, 67N-2 DELAY have elapsed, trip signals are issued. Signals are available for each element. The dropout threshold is roughly equal to 95% of the pickup value for currents greater than > 0.3 INom. Pickup can be stabilized by setting dropout times 1518 67 T DROP-OUT or 1618 67N T DROP-OUT. This time is started if the current falls below the threshold and maintains the pickup condition. The function thus does not drop out instantaneously. The trip delay time 67-2 DELAY or 67N-2 DELAY continues in the meantime. After the dropout delay time has elapsed, the pickup is reported OFF and the trip delay time is reset unless the threshold 67-2 PICKUP or 67N-2 PICKUP has been violated again. If the threshold is exceeded again while the dropout delay time is still running, it will be cancelled. The trip delay time 67-2 DELAY or 67N-2 DELAY continues in the meantime. If the threshold is still exceeded after the time has elapsed, a trip will be initiated immediately. If the threshold violation then no longer exists, there will be no response. If the threshold is exceeded again after the trip command delay time has elapsed and while the dropout delay time is still running, a trip will be initiated at once. These elements can be blocked by the automatic reclosure feature (AR). SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 90 2 Functions The following figure shows by way of example the logic diagram for the high-set element 67-2. Figure 2-19 Logic diagram of the directional high-current element 67-2 for phases If parameter MANUAL CLOSE is set to 67-2 instant. and manual close detection applies, the pickup is tripped instantaneously, also if the element is blocked via binary input. The same applies to 79 AR 67-2 instantaneous. 91 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.3 Directional Overcurrent Protection 67, 67N 2.3.3 Definite Time, Directional Overcurrent Elements 67-1, 67N-1 Phase and ground current are compared separately with the setting values 67-1 PICKUP and 67N-1 PICKUP of the respective relay elements. Currents above the setting values are signalled separately when fault direction is equal to the direction configured. If the inrush restraint feature is applied, either the normal pickup signals or the corresponding inrush signals are output as long as inrush current is detected. When, after pickup without inrush recognition, the relevant delay times 67-1 DELAY, 67N-1 DELAY have expired, a tripping command is issued. If the inrush restraint feature is enabled, and an inrush condition exists, no tripping takes place, but a message is recorded and displayed indicating when the overcurrent element time delay elapses. Tripping signals and signals on the expiration of time delay are available separately for each element. The dropout value is roughly equal to 95% of the pickup value for currents greater than > 0.3 INom. In addition, pickups can be stabilized by setting dropout times 1518 67 T DROP-OUT or 1618 67N T DROP-OUT. This time is started if the current falls below the threshold and maintains the pickup condition. The function thus does not drop out instantaneously. The trip delay time 67-1 DELAY or 67N-1 DELAY continues in the meantime. After the dropout delay time has elapsed, the pickup is reported OFF and the trip delay time is reset unless the threshold 67-1 PICKUP or 67N-1 PICKUP has been violated again. If the threshold is violated again while the dropout delay time is still running, it will be cancelled. The trip delay time 67-1 DELAY or 67N-1 DELAY continues in the meantime. If the threshold is still exceeded after the time has elapsed, a trip will be initiated immediately. If the threshold violation then no longer exists, there will be no response. If the threshold is violated again after the trip command delay time has elapsed and while the dropout delay time is still running, a trip will be initiated at once. Pickup stabilization of the overcurrent elements 67-1 or 67N-1 by means of settable dropout times is deactivated in the event of an inrush pickup, since an inrush is no intermittent fault. These elements can be blocked by the automatic reclosure feature (AR). SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 92 2 Functions The following figure shows by way of an example the logic diagram for the directional overcurrent element 67-1. Figure 2-20 Logic diagram for the directional overcurrent element 67-1 for phases The dropout delay only operates if no inrush was detected. An arriving inrush will reset an already running dropout delay time. 93 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.3 Directional Overcurrent Protection 67, 67N Figure 2-21 2.3.4 Logic of the dropout delay for 67-1 Inverse Time, Directional Overcurrent Protection Elements 67-TOC, 67N-TOC. Inverse time elements are dependent on the variant ordered. They operate either according to the IEC- or the ANSI-standard or to a user-defined characteristic. The curves and associated formulas are identical with those of the non-directional time overcurrent protection and are given in the Technical Specifications. When the inverse time curves are configured, the definite time relay elements (67-2, 67-1) are available. Pickup Behaviour Each phase and ground current is separately compared with the pickup values 67TOC PICKUP and 67N-TOC PICKUP of the respective relay elements. When a current value exceeds the corresponding setting value by a factor of 1.1, the corresponding phase picks up and a message is signalled phase-selectively assuming that the fault direction is equal to the direction configured. If the inrush restraint feature is applied, either the normal pickup signals or the corresponding inrush signals are output as long as inrush current is detected. Pickup of a relay element is based on the rms value of the fundamental harmonic. When the 67-TOC and 67N-TOC elements pick up, the time delay of the trip signal is calculated using an integrating measurement scheme. The calculated time delay is dependent on the actual fault current flowing and the selected tripping curve. Once the time delay elapses, a trip signal is issued assuming that no inrush current is detected or inrush restraint is disabled. If the inrush restraint feature is enabled and an inrush condition exists, no tripping takes place, but a message is recorded and displayed indicating when the overcurrent element time delay elapses. For ground current element 67N-TOC the characteristic may be selected independently of the characteristic used for phase currents. Pickup values of elements 67-TOC and 67N-TOC and the associated time multipliers may be individually set. Dropout Behaviour When using an IEC or ANSI curve select whether the dropout of an element is to occur instantaneously after the threshold has been undershot or whether dropout is to be performed by means of the disk emulation. "Instantaneously" means that pickup drops out when the pickup value of approx. 95 % of the set pickup value is undershot. For a new pickup the time counter starts at zero. The disk emulation evokes a dropout process (time counter is decrementing) which begins after de-energization. This process corresponds to the reset of a Ferraris-disk (explaining its denomination "disk emulation"). In case several faults occur in succession the "history" is taken into consideration due to the inertia of the Ferraris-disk and the time response is adapted. Reset begins as soon as 90% of the setting value is undershot, in accordance to the dropout curve of the selected characteristic. In the range between the dropout value (95% of the pickup value) and 90% of the setting value, the incrementing and the decrementing processes are in idle state. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 94 2 Functions Disk emulation offers advantages when the overcurrent relay elements must be coordinated with conventional electromechanical overcurrent relays located toward the source. User-defined Curves When user-defined characteristic are utilized, the tripping curve may be defined point by point. Up to 20 value pairs (current, time) may be entered. The device then approximates the characteristic, using linear interpolation. The dropout curve may be user-defined as well. This is advantageous when the overcurrent protection must be coordinated with conventional electromechanical overcurrent relays located toward the source. If no user-specified dropout curve is required, the element pickup drops out as soon as the measured signal is less than approx. 95% of the pickup setting. When a new pickup is evoked, the timer starts at zero again. 95 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.3 Directional Overcurrent Protection 67, 67N The following figure shows by way of an example the logic diagram for the 67-TOC relay element of the directional inverse time overcurrent protection of the phase currents. Figure 2-22 Logic diagram for the directional overcurrent protection: 67-TOC relay element SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 96 2 Functions 2.3.5 Interaction with the Fuse Failure Monitor (FFM) Spurious tripping can be caused by failure of a measuring voltage due to short-circuit, broken wire in the voltage transformer's secondary system or pickup of the voltage transformer fuse. Failure of the measuring voltage in one or two poles can be detected, and the directional time overcurrent elements (Dir Phase and Dir Ground) can be blocked (see logic diagrams). Undervoltage protection, sensitive ground fault detection and synchronization are equally blocked in this case. 2.3.6 Dynamic Cold Load Pickup Function It may be necessary to dynamically increase the pickup values of the directional time overcurrent protection if, at starting, certain elements of the system show an increased power consumption after a long period of zero voltage (e.g. air-conditioning systems, heating installations, motors). Thus, a general raise of pickup thresholds can be avoided taking into consideration such starting conditions. This dynamic pickup value changeover is common to all overcurrent elements and is described in Section 2.4. The alternative pickup values can be set individually for each element of the directional and non-directional time overcurrent protection. 2.3.7 Inrush Restraint The 7SJ62/63/64 features an integrated inrush restraint function. It prevents the "normal" pickup of all directional and non-directional overcurrent relay elements in the phases and ground path, but not the high-set elements. The same is true for the alternative pickup thresholds of the dynamic cold load pickup function. After detection of inrush currents above a pickup value special inrush signals are generated. These signals also initiate fault annunciations and start the associated trip delay time. If inrush conditions are still present after the tripping time delay has elapsed, a corresponding message ("....TimeOut ") is output, but the overcurrent tripping is blocked (for further information see "Inrush Restraint" in Section 2.2). 2.3.8 Determination of Direction Determination of fault direction is performed independently for each of the four directional elements (three phases, ground or summation current 3I0). Basically, the direction determination is performed by determining the phase angle between the fault current and a reference voltage. Method of Directional Measurement For the directional phase elements the short-circuit current of the affected phase and as reference voltage the unfaulted phase-to-phase voltage are used. The unfaulted voltage also allows an unambiguous direction determination if the fault voltage has collapsed severely (close-up fault). With phase-to-ground voltages connection, the phase-to-phase voltages are calculated. With connection to two phase-to-phase voltages and VN, the third phase-to-phase voltage is also calculated. With three-pole faults, stored voltage values are used to clearly determine the direction if the measurement voltages are not sufficient. After the expiration of the storage 97 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.3 Directional Overcurrent Protection 67, 67N time period (2 cycles), the detected direction is saved, as long as no sufficient measuring voltage is available. When closing onto a fault, if no stored voltage values exist in the buffer, the relay element will trip. In all other cases the voltage magnitude will be sufficient for determining the direction. Two methods are available to determine the direction for the directional ground fault element. Direction Determination with ZeroSequence System or Ground Quantities For the directional ground fault elements, direction can be determined by comparing the zero sequence system quantities. In the current path, the IN current is valid, when the transformer neutral current is connected to the device. Otherwise the device calculates the ground current from the sum of the three phase currents. In the voltage path, the displacement voltage VN is used as reference voltage, if it is connected. Otherwise the device calculates as reference voltage the zero-sequence voltage 3 * V0 from the sum of the three phase voltages. If the magnitude of VN or 3 * V0 is not sufficient to determine direction, the direction is undefined. Then the directional ground elements will not initiate a trip signal. If the current I0 cannot be determined, e.g. because only two current transformers are utilized or the current transformers are connected in an open delta configuration, then the directional ground elements will not be able to function. The latter is only permitted in ungrounded systems. Direction Determination with Negative Sequence System Here, the negative sequence current and as reference voltage the negative sequence voltage are used for the direction determination. This is advantageous if the zero sequence is influenced via a parallel line or if the zero voltage becomes very small due to unfavorable zero impedances. The negative sequence system is calculated from the individual voltages and currents. As with the use of the zero sequence values, a direction determination is carried out if the values necessary for the direction determination have exceeded a minimum threshold. Otherwise the direction is undetermined. Cross-Polarized Reference Voltages for Direction Determination A 2-pole short circuit is detected by two directional phase elements, i.e. the directional phase elements associated with the faulted phases. A single-pole fault (ground fault) is detected by the directional ground element, and may be detected by the directional phase elements associated with the faulted phases if the magnitude of the fault current is sufficient to pickup the directional element. For the directional ground fault elements, naturally, pre-described connection requirements must be fulfilled. For a phase-to-ground fault, the voltage (reference voltage) used by the directional phase element of the faulted phase is 90 out of phase with the phase-to-ground voltage of the faulted phase at the relay location (see Figure 2-23). With phase-tophase faults, the angle between the unfaulted voltages (reference voltages) and the fault voltages can be between 90 (remote fault) and 60 (close-up fault) depending on the degree of collapse of the fault voltages. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 98 2 Functions Figure 2-23 Cross-polarized voltages for direction determination The following table shows the assignment of measured values for the determination of fault direction for various types of pickups. Table 2-6 Measured values for the determination of fault direction PICKUP Directional Element A A B C N Current Voltage Current Voltage Current Voltage Current Voltage IA VB - VC -- -- -- -- -- -- B -- -- IB VC - VA -- -- -- -- C -- -- -- -- IC VA - VB -- -- N -- -- -- -- -- -- IN VN1) A, N IA VB - VC -- -- -- -- IN VN1) B, N -- -- IB VC - VA -- -- IN VN1) C, N -- -- -- -- IC VA - VB IN VN1) A, B IA VB - VC IB VC - VA -- -- -- -- B, C -- -- IB VC - VA IC VA - VB -- -- A, C IA VB - VC -- -- IC VA - VB -- -- A, B, N IA VB - VC IB VC - VA -- -- IN VN1) B, C, N -- -- IB VC - VA IC VA - VB IN VN A, C, N IA VB - VC -- -- IC VA - VB IN VN1) A, B, C IA VB - VC IB VC - VA IC VA - VB -- -- A, B, C, N IA VB - VC IB VC - VA IC VA - VB IN VN1) 1) Direction Determination of Directional Phase Elements 99 or 3 * V0 = |VA + VB + VC|, depending on type of connection for the voltages As already mentioned, the direction determination is performed by determining the phase angle between the fault current and the reference voltage. In order to satisfy different network conditions and applications, the reference voltage can be rotated through an adjustable angle. In this way, the vector of the rotated reference voltage can be closely adjusted to the vector of the fault current in order to provide the best possible result for the direction determination. Figure 2-24 clearly shows the relationship for the directional phase elements based on a single-pole ground fault in Phase A. The fault current IscA follows the fault voltage by the fault angle sc. The reference voltage, in this case VBC for the directional phase element A, is rotated through the SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.3 Directional Overcurrent Protection 67, 67N setting value 1519 ROTATION ANGLE, positive counter-clockwise. In this case, a rotation of +45. Figure 2-24 Rotation of the reference voltage, directional phase element The rotated reference voltage defines the forward and backward area, see Figure 225. The forward area is a range of 86 around the rotated reference voltage Vref, rot. If the vector of the fault current is in this area, the device detects forward direction. In the mirrored area, the device detects backward direction. In the intermediate area, the direction result is undefined. Figure 2-25 Direction Determination of Directional Ground Element with Ground Values Forward characteristic of the directional function, directional phase element Figure 2-26 shows the treatment of the reference voltage for the directional ground element, also based on a single-pole ground fault in Phase A. Contrary to the directional phase elements, which work with the unfaulted voltage as reference voltage, the fault voltage itself is the reference voltage for the directional ground element. Depending on the connection of the voltage transformer, this is the voltage 3V0 (as shown in SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 100 2 Functions Figure 2-26) or VN. The fault current -3I0 is in phase oposition to the fault current IscA and follows the fault voltage 3V0 by the fault angle sc. The reference voltage is rotated through the setting value 1619 ROTATION ANGLE. In this case, a rotation of -45. Figure 2-26 Rotation of the reference voltage, directional ground element with zero sequence values The forward area is also a range of 86 around the rotated reference voltage Vref, rot. If the vector of the fault current -3I0 (or IN) is in this area, the device detects forward direction. Direction Determination of Directional Ground Element with Negative Sequence Values Figure 2-27 shows the treatment of the reference voltage for the directional ground element using the negative sequence values based on a single-pole ground fault in Phase A. As reference voltage, the negative sequence system voltage is used, as current for the direction determination, the negative sequence system current, in which the fault current is displayed. The fault current -3I2 is in phase oposition to the fault current IscA and follows the voltage 3V2 by the fault angle sc. The reference voltage is rotated through the setting value 1619 ROTATION ANGLE. In this case, a rotation of -45. Figure 2-27 101 Rotation of the reference voltage, directional ground element with negative sequence values SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.3 Directional Overcurrent Protection 67, 67N The forward area is a range of 86 around the rotated reference voltage Vref, rot. If the vector of the negative sequence system current -3I2 is in this area, the device detects forward direction. 2.3.9 Reverse Interlocking for Double End Fed Lines Application Example The directionality feature of the directional overcurrent protection enables the user to perform reverse interlocking also on double end fed lines using relay element 67-1. It is designed to selectively isolate a faulty line section (e.g. sections of rings) in high speed, i.e. no long graded times will slow down the process. This scheme is feasible when the distance between protective relays is not too great and when pilot wires are available for signal transfer via an auxiliary voltage loop. For each line, a separate data transfer path is required to facilitate signal transmission in each direction. When implemented in a closed-circuit connection, disturbances in the communication line are detected and signalled with time delay. The local system requires a local interlocking bus wire similar to the one described in Subsection "Reverse Interlocking Bus Protection" for the directional overcurrent protection (Section 2.2). During a line fault, the device that detects faults in forward (line) direction using the directional relay element 67-1 will block one of the non-directional overcurrent elements (50-1, 50-TOC) of devices in the reverse direction (at the same busbar) since they should not trip (Figure 2-28). In addition, a message is generated regarding the fault direction. "Forward" messages are issued when the current threshold of the directional relay element 67-1 is exceeded and directional determination is done. Subsequently, "forward" messages are transmitted to the device located in reverse direction. During a busbar fault, the device that detects faults in reverse (busbar) direction using the directional relay element 67-1 will block one of the non-directional overcurrent elements (50-1, 50-TOC) of devices at the opposite end of the same feeder. In addition, a "Reverse" message is generated and transmitted via the auxiliary voltage loop to the relay located at the opposite end of the line. Figure 2-28 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 Reverse interlocking using directional elements 102 2 Functions The directional overcurrent element providing normal time grading operates as selective backup protection. The following figure shows the logic diagram for the generation of fault direction signals. Figure 2-29 Logic diagram for the generation of fault direction signals. 2.3.10 Setting Notes General When selecting the directional time overcurrent protection in DIGSI, a dialog box appears with several tabs for setting the associated parameters. Depending on the functional scope specified during configuration of the protective functions in addresses 115 67/67-TOC and 116 67N/67N-TOC, the number of tabs can vary. If 67/67-TOC or 67N/67N-TOC = Definite Time is selected, then only the settings for the definite time elements are available. If TOC IEC or TOC ANSI is selected, the inverse characteristics are also available. The superimposed directional elements 672 and 67-1 or 67N-2 and 67N-1 apply in all these cases. At address 1501 FCT 67/67-TOC, directional phase overcurrent protection may be switched ON or OFF. Pickup values, time delays, and characteristic are set separately for phase protection and ground protection. Because of this, relay coordination for ground faults is independent of relay coordination for phase faults, and more sensitive settings can often be applied to directional ground protection. Thus, at address 1601 FCT 67N/67N-TOC, directional ground time overcurrent protection may be switched ON or OFF independent of the directional phase time overcurrent protection. Depending on the parameter 613 Gnd O/Cprot. w., the device can either operate using measured values IN or the quantities 3I0 calculated from the three phase currents. Devices featuring a sensitive ground current input generally use the calculated quantity 3I0. The direction determination of the function is affected by parameter 201 CT Starpoint (see chapter 2.1.3). 103 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.3 Directional Overcurrent Protection 67, 67N Direction Characteristic The direction characteristic, i.e. the position of the ranges forward" and backward" is set for the phase directional elements under address 1519 ROTATION ANGLE and for the ground directional element under address 1619 ROTATION ANGLE. The shortcircuit angle is generally inductive in a range of 30 to 60. I.e., usually the default settings of +45 for the phase directional elements and -45 for the ground directional element can be maintained for the adjustment of the reference voltage, as they guarantee a safe direction result. Nevertheless, the following contains some setting examples for special applications (Table 2-7). The following must be observed: With the phase directional elements, the reference voltage (fault-free voltage) for phase-ground-faults is vertical on the shortcircuit voltage. For this reason, the resulting setting of the angle of rotation is (see also Section 2.3.8): Angle of rotation of ref. volt. = 90 - sc phase directional element (phase-ground fault) With the ground directional element, the reference voltage is the short-circuit voltage itself. The resulting setting of the angle of rotation is then: Angle of rotation of ref. volt. = -sc ground directional element (phase-ground fault) It should also be noted for phase directional elements that with phase-to-phase faults, the reference voltage is rotated between 0 (remote fault) and 30 (close-up fault) depending on the collapse of the faulty voltage. This can be taken into account with a mean value of 15: Angle of rotation of ref. volt. = 90 - sc -15 phase directional element (phase-to-phase fault). SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 104 2 Functions Table 2-7 Setting example sc typical Application Phase directional element setting Ground directional element setting 1519 ROTATION ANGLE 1619 ROTATION ANGLE 1) 2) 60 Range 30...0 15 -60 30 Range 60...30 45 -30 30 Range 60...30 45 -30 Power flow direction With the assumption that these are cable lines Before Version V4.60, the direction characteristic could only be set in three discrete positions. In the following, the settings are specified which correspond to the old parameters 1515 and 1615. Up to V4.60 Addr. 1515 / 1615 Phase directional elements Ground directional element Addr. 1519 Addr. 1619 451) -451) Resistive (90) 90 0 Capacitive (45) 135 45 Inductive 1) Directional Orientation 105 As of V4.60 (135)1) Default Setting The directional orientation can be changed for the phase directional elements under address 1516 67 Direction and for the ground directional element under address 1616 67N Direction. Directional overcurrent protection normally operates in the direction of the protected object (line, transformer). If the protection device is properly connected in accordance with one of the circuit diagrams in Appendix A.3, this is the forward" direction. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.3 Directional Overcurrent Protection 67, 67N Quantity Selection for the Direction Determination for the Ground Directional Element Parameter 1617 67N POLARIZAT. can be set to specify whether direction determination is accomplished from the zero sequence quantities, the ground quantities (with VN and IN) or the negative sequence quantities (with V2 and I2) in the ground directional element. The first option is the preferential setting; the latter should be selected if there is the risk of the zero sequence voltage becoming extremely small due to unfavorable zero sequence impedance or a parallel line influencing the zero sequence system. 67-2 Directional High-set Element (Phases) The pickup and delay of element 67-2 are set at addresses 1502 and 1503. For setting, the same considerations apply as did for the non-directional time overcurrent protection in Section 2.2.10. The selected time is only an additional time delay and does not include the operating time (measuring time, dropout time). The delay can be set to . After pickup the element will then not trip. Pickup, however, will be signaled. If the 67-2 element is not required at all, the pickup value 67-2 PICKUP should be set to . For this setting, there is neither a pickup signal generated nor a trip. 67N-2 Directional High-set Element (Ground) The pickup and delay of element 67N-2 are set at addresses 1602 and 1603. The same considerations apply for these settings as did for phase currents discussed earlier. The selected time is only an additional time delay and does not include the operating time (measuring time, dropout time). The delay can be set to . After pickup the element will then not trip. Pickup, however, will be signaled. If the 67N-2 element is not required at all, then the pickup value 67N-2 PICKUP should be set to . This setting prevents from tripping and the generation of a pickup message. 67-1 Directional Overcurrent Element (Phases) The pickup value of the 67-1 relay element 1504 67-1 PICKUP should be set above the maximum anticipated load current. Pickup due to overload should never occur, since the device in this operating mode operates as short circuit protection with correspondingly short tripping times and not as overload protection. For this reason, lines are set to approx. 20% above the maximum expected (over)load and transformers and motors to approx. 40%. If the relay is used to protect transformers or motors with large inrush currents, the inrush restraint feature of 7SJ62/63/64 may be used for the 67-1 relay element (for more information see margin heading "Inrush Restraint"). The delay for directional elements (address 1505 67-1 DELAY) is usually set shorter than the delay for non-directional elements (address 1205) since the non-directional elements overlap the directional elements as backup protection. It should be based on the system coordination requirements for directional tripping. For parallel transformers supplied from a single source (see "Usecases"), the delay of elements 67-1 DELAY located on the load side of the transformers may be set to 0 without provoking negative impacts on selectivity. The selected time is only an additional time delay and does not include the operating time (measuring time, dropout time). The delay can be set to . After pickup the element will then not trip. Pickup, however, will be signaled. If the 67-1 element is not required at all, the pickup value 67-1 PICKUP should be set to . This setting prevents from tripping and the generation of a pickup message. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 106 2 Functions 67N-1 Directional Relay Element (ground) The pickup value of the 67N-1 relay element should be set below the minimum anticipated ground fault current. If the relay is used to protect transformers or motors with large inrush currents, the inrush restraint feature of 7SJ62/63/64 may be used for the 67N-1 relay element (for more information see margin heading "Inrush Restraint"). The delay is set at address 1605 67N-1 DELAY and should be based on system coordination requirements for directional tripping. For ground currents in a grounded system a separate coordination chart with short time delays is often used. The selected time is only an additional time delay and does not include the operating time (measuring time, dropout time). The delay can be set to . After pickup the element will then not trip. Pickup, however, will be signaled. If the 67N-1 element is not required at all, the pickup value 67N-1 PICKUP should be set to . This setting prevents from tripping and the generation of a pickup message. Pickup Stabilization (67/67N Directional) Pickup of the direction 67/67N elements can be stabilized by setting dropout times 1518 67 T DROP-OUT or 1618 67N T DROP-OUT. 67-TOC Directional Element with IEC or ANSI Curves (Phases) Having set address 115 67/67-TOC = TOC IEC or TOC ANSI when configuring the protective functions (Section 2.1.1), the parameters for the inverse characteristics will also be available. If the relay is used to protect transformers or motors with large inrush currents, the inrush restraint feature of 7SJ62/63/64 may be used for the 67-TOC relay element (for more information see margin heading "Inrush Restraint"). If the inverse time trip characteristic is selected, it must be noted that a safety factor of about 1.1 has already been included between the pickup value and the setting value. This means that a pickup will only occur if a current of about 1.1 times the setting value is present. The current value is set in address 1507 67-TOC PICKUP. The setting is mainly determined by the maximum operating current. Pickup due to overload should never occur, since the device in this operating mode operates as fault protection with correspondingly short tripping times and not as overload protection. The corresponding element time multiplication factor for an IEC characteristic is set at address 1508 67 TIME DIAL and in address 1509 67 TIME DIAL for an ANSI characteristic. It must be coordinated with the time grading of the network. The time multiplier can also be set to . After pickup the element will then not trip. Pickup, however, will be signaled. If the 67-TOC element is not required at all, address 115 67/67-TOC should be set to Definite Time during protective function configuration (see Section 2.1.1). If address 115 67/67-TOC = TOC IEC, you can specify the desired IEC- characteristic (Normal Inverse, Very Inverse, Extremely Inv. or Long Inverse) in address 1511 67- IEC CURVE. If address 115 67/67-TOC = TOC ANSI you can specify the desired ANSI-characteristic (Very Inverse, Inverse, Short Inverse, Long Inverse, Moderately Inv., Extremely Inv. or Definite Inv.) in address 1512 67- ANSI CURVE. 107 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.3 Directional Overcurrent Protection 67, 67N 67N-TOC Directional Element with IEC or ANSI Curves (ground) Having set address 116 67N/67N-TOC = TOC IEC when configuring the protective functions (Section 2.1.1), the parameters for the inverse characteristics will also be available. Specify in address 1611 67N-TOC IEC the desired IEC characteristic (Normal Inverse, Very Inverse, Extremely Inv. or Long Inverse). If address 116 67N/67N-TOC = TOC ANSI, you can specify the desired ANSI- characteristic (Very Inverse, Inverse, Short Inverse, Long Inverse, Moderately Inv., Extremely Inv. or Definite Inv.) in address 1612 67NTOC ANSI. If the relay is used to protect transformers or motors with large inrush currents, the inrush restraint feature of 7SJ62/63/64 may be used for the 67N-TOC relay element (for more information see margin heading "Inrush Restraint"). If the inverse time trip characteristic is selected, it must be noted that a safety factor of about 1.1 has already been included between the pickup value and the setting value 67N-TOC PICKUP. This means that a pickup will only occur if a current of about 1.1 times the setting value is present. If Disk Emulation was selected at address 1610 67N-TOC DropOut, reset will occur in accordance with the reset curve as for the existing non-directional time overcurrent protection described in Section 2.2. The current value is set at address 1607 67N-TOC PICKUP. The minimum appearing ground fault current is most relevant for this setting. The corresponding element time multiplication factor for an IEC characteristic is set at address 1608 67N-TOC T-DIAL and in address 1609 67N-TOC T-DIAL for an ANSI characteristic. This has to be coordinated with the system grading coordination chart for directional tripping. For ground currents with grounded network, you can mostly set up a separate grading coordination chart with shorter delay times. The time multiplier can also be set to . After pickup the element will then not trip. Pickup, however, will be signaled. If the 67N-TOC element is not required at all, address 116 67N/67N-TOC should be set to Definite Time during protective function configuration (see Section 2.1.1). User-defined characteristic (Inverse Time Phases and ground) If address 115 or 116 were set to User Defined PU or User def. Reset during configuration of the user-defined characteristic option, a maximum of 20 value pairs (current and time) may be entered at address 1530 67 or 1630 M.of PU TD. This option allows point-by-point entry of any desired curve. If address 115 or 116 were set to User def. Reset during configuration, additional value pairs (current and reset time) may be entered in address 1531 MofPU Res T/Tp or 1631 I/IEp Rf T/TEp to represent the reset curve. Entry of the value pair (current and time) is a multiple of the settings of the values of the addresses 1507 67-TOC PICKUP or 1607 67N-TOC PICKUP and 1508 67 TIME DIAL or 1608. 67N-TOC T-DIAL. Therefore, it is recommended that parameter values are initially set to 1.00 for simplicity. Once the curve is entered, the settings at addresses 1507 and 1607 or/and 1508 and 1608 may be modified later on if necessary. The default setting of current values is . They are, therefore, not enabled -- and no pickup or tripping of these protective functions will occur. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 108 2 Functions The following must be observed: * The value pairs should be entered in increasing sequence. If desired, fewer than 20 pairs may be entered. In most cases, about 10 pairs is sufficient to define the characteristic accurately. A value pair which will not be used has to be made invalid entering " for the threshold! The user must ensure the value pairs produce a clear and constant characteristic. The current values entered should be those from the following Table, along with the matching times. Deviating values I/Ip are rounded. This, however, will not be indicated. Current flows less than the smallest current value entered will not lead to an extension of the tripping time. The pickup curve (see Figure 2-13, right side) goes parallel to the current axis, up to the smallest current point. Current flows greater than the highest current value entered will not lead to a reduction of the tripping time. The pickup characteristic (see Figure 2-13, right side) goes parallel to the current axis, beginning with the greatest current point. Table 2-8 Preferential values of standardized currents for user-defined tripping curves I/Ip = 1 to 1.94 1.00 1.50 I/Ip = 2 to 4.75 2.00 3.50 I/Ip = 5 to 7.75 5.00 6.50 I/Ip = 8 to 20 8.00 15.00 1.06 1.56 2.25 3.75 5.25 6.75 9.00 16.00 1.13 1.63 2.50 4.00 5.50 7.00 10.00 17.00 1.19 1.69 2.75 4.25 5.75 7.25 11.00 18.00 1.25 1.75 3.00 4.50 6.00 7.50 12.00 19.00 1.31 1.81 3.25 4.75 6.25 7.75 13.00 20.00 1.38 1.88 1.44 1.94 14.00 The value pairs are entered at address 1531 MofPU Res T/Tp to recreate the reset curve. The following must be observed: * The current values entered should be those from Table 2-8, along with the matching times. Deviating values I/Ip are rounded. This, however, will not be indicated. Current flows greater than the highest current value entered will not lead to a prolongation of the reset time. The reset curve (see Figure 2-13, left side) is parallel to the current axis, beginning with the largest current point. Current flows which are less than the smallest current value entered will not lead to a reduction of the reset time. The reset curve (see Figure 2-13, left side) is parallel to the current axis, beginning with the smallest current point. 109 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.3 Directional Overcurrent Protection 67, 67N Table 2-9 Preferential values of standardized currents for user-defined reset curves I/Ip = 1 to 0.86 I/Ip = 0.84 to 0.67 I/Ip = 0.66 to 0.38 I/Ip = 0.34 to 0.00 1.00 0.93 0.84 0.75 0.66 0.53 0.34 0.16 0.99 0.92 0.83 0.73 0.64 0.50 0.31 0.13 0.98 0.91 0.81 0.72 0.63 0.47 0.28 0.09 0.97 0.90 0.80 0.70 0.61 0.44 0.25 0.06 0.96 0.89 0.78 0.69 0.59 0.41 0.22 0.03 0.95 0.88 0.77 0.67 0.56 0.38 0.19 0.00 0.94 0.86 Figure 2-30 Using a user-defined curve Inrush Restraint When applying the protection device to transformers where high inrush currents are to be expected, the 7SJ62/63/64 can make use of an inrush restraint function for the directional overcurrent elements 67-1, 67-TOC, 67N-1 and 67N-TOC as well as the non-directional overcurrent elements. The inrush restraint option is enabled or disabled in 2201 INRUSH REST. (in the settings option non-directional time overcurrent protection). The characteristic values of the inrush restraint are already listed in the section discussing the non-directional time overcurrent (Section 2.2.10). Manual Close Mode (Phases, ground) When a circuit breaker is closed onto a faulted line, a high speed trip by the circuit breaker is often desired. For overcurrent or high-set element the delay may be bypassed via via a "Manual Close" signal, thus resulting in instantaneous tripping. The internal "Manual close" signal is built from the binary input signal >Manual Close" (no. 561). The internal "Manual close" signal remains active as long as the binary input signal >Manual Close" is active, but at lease for 300 ms (see the following logic diagram). To enable the device to react properly on occurrence of a fault in the phase elements after manual close, address 1513 MANUAL CLOSE has to be set accordingly. Accordingly, address 1613 MANUAL CLOSE is considered for the ground path address. Thus, the user determines for both elements, the phase and the ground element, what pickup value is active with what delay when the circuit breaker is closed manually. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 110 2 Functions Figure 2-31 Manual close feature External Control Switch If the manual closing signal is not from a 7SJ62/63/64 relay, that is, neither sent via the built-in operator interface nor via a series interface, but, rather, directly from a control acknowledgment switch, this signal must be passed to a 7SJ62/63/64 binary input, and configured accordingly (>Manual Close"), so that the element selected for MANUAL CLOSE will be effective. Inactive means that the element operates as configured even with manual close. Internal Control Function The manual closing information must be allocated via CFC (interlocking task-level) using the CMD_Information block, if the internal control function is used. Figure 2-32 Example for manual close feature using the internal control function Note For an interaction between the automatic reclosure (AR) and the control function, an extended CFC logic is necessary. See margin heading CLOSE command: Directly or via control" in the Setting Notes of the AR function (Section 2.14.6). Interaction with Automatic Reclosure Function (Phases) When reclosing occurs, it is desirable to have high speed protection against faults with 67-2. If the fault still exists after the first reclosure, elements 67-1 or 67-TOC will be initiated with graded tripping times, i.e., the 67-2 elements will be blocked. At address 1514 67 active, it can be specified whether (with 79 active) or not (Always) the 67-2 elements should be supervised by the status of an internal or external automatic reclosing device. Address with 79 active determines that the 67-2 elements will not operate unless automatic reclosing is not blocked. If not desired, then setting Always is selected having the effect that the 67-2 elements will always operate, as configured. The integrated automatic reclosing function of 7SJ62/63/64 also provides the option to individually determine for each time overcurrent element whether instantaneous tripping, i.e. normal time delayed tripping unaffected by the automatic reclosing, or blocking shall take place (see Section 2.14). Interaction with Automatic Reclosing Function (ground) 111 When reclosing occurs, it is desirable to have high speed protection against faults with 67N-2. If the fault still exists after the first reclosure, elements 67N-1 or 67N-TOC will be initiated with graded tripping times, i.e. the 67N-2 elements will be blocked. At address 1614 67N active, it can be specified whether (with 79 active) or not SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.3 Directional Overcurrent Protection 67, 67N (Always) the 67N-2 elements should be supervised by the status of an internal or external automatic reclosing device. Address with 79 active determines that the 67N-2 elements will not operate unless automatic reclosing is not blocked. If not desired, then setting Always is selected having the effect that the 67N-2 elements will always operate, as configured. The integrated automatic reclosing function of 7SJ62/63/64 also provides the option to individually determine for each time overcurrent element whether instantaneous tripping, i.e. normal time delayed tripping unaffected by the automatic reclosing, or blocking shall take place (see Section 2.14). SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 112 2 Functions 2.3.11 Settings Addresses which have an appended "A" can only be changed with DIGSI, under "Display Additional Settings". The table indicates region-specific default settings. Column C (configuration) indicates the corresponding secondary nominal current of the current transformer. Addr. Parameter 1501 FCT 67/67-TOC 1502 67-2 PICKUP 1503 67-2 DELAY 1504 67-1 PICKUP 1505 67-1 DELAY 1507 67-TOC PICKUP C Setting Options Default Setting Comments OFF ON OFF 67, 67-TOC Phase Time Overcurrent 1A 0.10 .. 35.00 A; 2.00 A 67-2 Pickup 5A 0.50 .. 175.00 A; 10.00 A 0.00 .. 60.00 sec; 0.10 sec 67-2 Time Delay 1A 0.10 .. 35.00 A; 1.00 A 67-1 Pickup 5A 0.50 .. 175.00 A; 5.00 A 0.00 .. 60.00 sec; 0.50 sec 67-1Time Delay 1A 0.10 .. 4.00 A 1.00 A 67-TOC Pickup 5A 0.50 .. 20.00 A 5.00 A 1508 67 TIME DIAL 0.05 .. 3.20 sec; 0.50 sec 67-TOC Time Dial 1509 67 TIME DIAL 0.50 .. 15.00 ; 5.00 67-TOC Time Dial 1510 67-TOC Drop-out Instantaneous Disk Emulation Disk Emulation Drop-Out Characteristic 1511 67- IEC CURVE Normal Inverse Very Inverse Extremely Inv. Long Inverse Normal Inverse IEC Curve 1512 67- ANSI CURVE Very Inverse Inverse Short Inverse Long Inverse Moderately Inv. Extremely Inv. Definite Inv. Very Inverse ANSI Curve 1513A MANUAL CLOSE 67-2 instant. 67-1 instant. 67-TOC instant. Inactive 67-2 instant. Manual Close Mode 1514A 67 active with 79 active always always 67 active 1516 67 Direction Forward Reverse Forward Phase Direction 1518A 67 T DROP-OUT 0.00 .. 60.00 sec 0.00 sec 67 Drop-Out Time Delay 1519A ROTATION ANGLE -180 .. 180 45 Rotation Angle of Reference Voltage 1530 67 1.00 .. 20.00 I/Ip; 0.01 .. 999.00 TD 113 67 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.3 Directional Overcurrent Protection 67, 67N Addr. Parameter C Setting Options Default Setting Comments 1531 MofPU Res T/Tp 0.05 .. 0.95 I/Ip; 0.01 .. 999.00 TD 1601 FCT 67N/67N-TOC OFF ON OFF 67N, 67N-TOC Ground Time Overcurrent 1602 67N-2 PICKUP 1A 0.05 .. 35.00 A; 0.50 A 67N-2 Pickup 5A 0.25 .. 175.00 A; 2.50 A 0.00 .. 60.00 sec; 0.10 sec 67N-2 Time Delay 1A 0.05 .. 35.00 A; 0.20 A 67N-1 Pickup 5A 0.25 .. 175.00 A; 1.00 A 0.00 .. 60.00 sec; 0.50 sec 67N-1 Time Delay 1A 0.05 .. 4.00 A 0.20 A 67N-TOC Pickup 5A 0.25 .. 20.00 A 1.00 A 1603 67N-2 DELAY 1604 67N-1 PICKUP 1605 67N-1 DELAY 1607 67N-TOC PICKUP Multiple of Pickup <-> T/Tp 1608 67N-TOC T-DIAL 0.05 .. 3.20 sec; 0.20 sec 67N-TOC Time Dial 1609 67N-TOC T-DIAL 0.50 .. 15.00 ; 5.00 67N-TOC Time Dial 1610 67N-TOC DropOut Instantaneous Disk Emulation Disk Emulation Drop-Out Characteristic 1611 67N-TOC IEC Normal Inverse Very Inverse Extremely Inv. Long Inverse Normal Inverse IEC Curve 1612 67N-TOC ANSI Very Inverse Inverse Short Inverse Long Inverse Moderately Inv. Extremely Inv. Definite Inv. Very Inverse ANSI Curve 1613A MANUAL CLOSE 67N-2 instant. 67N-1 instant. 67N-TOC instant Inactive 67N-2 instant. Manual Close Mode 1614A 67N active always with 79 active always 67N active 1616 67N Direction Forward Reverse Forward Ground Direction 1617 67N POLARIZAT. with VN and IN with V2 and I2 with VN and IN Ground Polarization 1618A 67N T DROP-OUT 0.00 .. 60.00 sec 0.00 sec 67N Drop-Out Time Delay 1619A ROTATION ANGLE -180 .. 180 -45 Rotation Angle of Reference Voltage 1630 M.of PU TD 1.00 .. 20.00 I/Ip; 0.01 .. 999.00 TD Multiples of PU Dial 1631 I/IEp Rf T/TEp 0.05 .. 0.95 I/Ip; 0.01 .. 999.00 TD 67N TOC SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 Time- 114 2 Functions 2.3.12 Information List No. Information Type of Information Comments 2604 >BLK 67/67-TOC SP >BLOCK 67/67-TOC 2614 >BLK 67N/67NTOC SP >BLOCK 67N/67N-TOC 2615 >BLOCK 67-2 SP >BLOCK 67-2 2616 >BLOCK 67N-2 SP >BLOCK 67N-2 2621 >BLOCK 67-1 SP >BLOCK 67-1 2622 >BLOCK 67-TOC SP >BLOCK 67-TOC 2623 >BLOCK 67N-1 SP >BLOCK 67N-1 2624 >BLOCK 67N-TOC SP >BLOCK 67N-TOC 2628 Phase A forward OUT Phase A forward 2629 Phase B forward OUT Phase B forward 2630 Phase C forward OUT Phase C forward 2632 Phase A reverse OUT Phase A reverse 2633 Phase B reverse OUT Phase B reverse 2634 Phase C reverse OUT Phase C reverse 2635 Ground forward OUT Ground forward 2636 Ground reverse OUT Ground reverse 2637 67-1 BLOCKED OUT 67-1 is BLOCKED 2642 67-2 picked up OUT 67-2 picked up 2646 67N-2 picked up OUT 67N-2 picked up 2647 67-2 Time Out OUT 67-2 Time Out 2648 67N-2 Time Out OUT 67N-2 Time Out 2649 67-2 TRIP OUT 67-2 TRIP 2651 67/67-TOC OFF OUT 67/67-TOC switched OFF 2652 67 BLOCKED OUT 67/67-TOC is BLOCKED 2653 67 ACTIVE OUT 67/67-TOC is ACTIVE 2655 67-2 BLOCKED OUT 67-2 is BLOCKED 2656 67N OFF OUT 67N/67N-TOC switched OFF 2657 67N BLOCKED OUT 67N/67N-TOC is BLOCKED 2658 67N ACTIVE OUT 67N/67N-TOC is ACTIVE 2659 67N-1 BLOCKED OUT 67N-1 is BLOCKED 2660 67-1 picked up OUT 67-1 picked up 2664 67-1 Time Out OUT 67-1 Time Out 2665 67-1 TRIP OUT 67-1 TRIP 2668 67N-2 BLOCKED OUT 67N-2 is BLOCKED 2669 67-TOC BLOCKED OUT 67-TOC is BLOCKED 2670 67-TOC pickedup OUT 67-TOC picked up 2674 67-TOC Time Out OUT 67-TOC Time Out 2675 67-TOC TRIP OUT 67-TOC TRIP 2676 67-TOC DiskPU OUT 67-TOC disk emulation is ACTIVE 2677 67N-TOC BLOCKED OUT 67N-TOC is BLOCKED 2679 67N-2 TRIP OUT 67N-2 TRIP 2681 67N-1 picked up OUT 67N-1 picked up 2682 67N-1 Time Out OUT 67N-1 Time Out 2683 67N-1 TRIP OUT 67N-1 TRIP 115 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.3 Directional Overcurrent Protection 67, 67N No. Information 2684 67N-TOCPickedup 2685 2686 Type of Information Comments OUT 67N-TOC picked up 67N-TOC TimeOut OUT 67N-TOC Time Out 67N-TOC TRIP OUT 67N-TOC TRIP 2687 67N-TOC Disk PU OUT 67N-TOC disk emulation is ACTIVE 2691 67/67N pickedup OUT 67/67N picked up 2692 67 A picked up OUT 67/67-TOC Phase A picked up 2693 67 B picked up OUT 67/67-TOC Phase B picked up 2694 67 C picked up OUT 67/67-TOC Phase C picked up 2695 67N picked up OUT 67N/67N-TOC picked up 2696 67/67N TRIP OUT 67/67N TRIP SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 116 2 Functions 2.4 Dynamic Cold Load Pickup With the cold load pickup function, pickup and delay settings of directional and nondirectional time overcurrent protection can be changed over dynamically. Applications * It may be necessary to dynamically increase the pickup values if, during starting and for a short time thereafter, certain elements of the system have an increased power consumption after a long period of zero voltage (e.g. air-conditioning systems, heating installations, motors). Thus a raise of pickup thresholds can be avoided by taking into consideration such starting conditions. * As a further option the pickup thresholds may be modified by an automatic reclosure function in accordance with its ready or not ready state. Prerequisites Note: Dynamic cold load pickup is not be confused with the changeover option of the 4 setting groups (A to D). It is an additional feature. It is possible to change pickup thresholds and delay times. 2.4.1 Effect Description There are two methods by which the device can determine if the protected equipment is de-energized: * Via binary inputs, the device is informed of the position of the circuit breaker (address 1702 Start Condition = Breaker Contact). * As a criterion a set current threshold is undershot (address 1702 Start Condition = No Current). If the device determines that the protected equipment is de-energized via one of the above methods, a time, CB Open Time, is started and after its expiration the increased thresholds take effect. In addition, switching between parameters can be triggered by two further events: * by signal "79M Auto Reclosing ready" of the internal automatic reclosure function (address 1702 Start Condition = 79 ready). Thus the protection thresholds and the tripping times can be changed if automatic reclosure is ready for reclosing (see also Section 2.14). * Irrespective of the setting of parameter 1702 Start Condition the release of cold load pickup may always be selected via the binary input >ACTIVATE CLP". Figure 2-34 shows the logic diagram for dynamic cold load pickup function. When the auxiliary contact or current criterion detects that the system is de-energized, i.e. the circuit breaker is open, the CB open time CB Open Time is started. As soon as it times out, the greater thresholds are enabled. When the protected equipment is re-energized (the device receives this information via the binary inputs or when threshold BkrClosed I MIN is exceeded), a second time delay referred to as the Active Time is initiated. Once it elapses, the pickup values of the relay elements return to their normal settings. The time may be reduced when current values after startup, i.e. after the circuit breaker is closed, fall below all normal pickup values for a set time, Stop Time. The starting condition of the fast reset time is made up of an OR-combination of the configured dropout conditions of all non-directional time overcurrent elements. When Stop Time is set to or when binary input >BLK CLP stpTim" is 117 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.4 Dynamic Cold Load Pickup active, no comparison is made with the "normal" thresholds. The function is inactive and the fast reset time, if applied, is reset. If overcurrent elements are picked up while time Active Time is running, the fault generally prevails until pickup drops out, using the dynamic settings. Only then the parameters are set back to "normal". When the dynamic setting values are activated via the binary input >ACTIVATE CLP" or the signal "79M Auto Reclosing ready" and this causes drops out, the "normal" settings are restored immediately, even if a pick up is the result. When binary input >BLOCK CLP" is enabled, all triggered timers will be reset and, as a consequence, all "normal" settings will be immediately restored. If blocking occurs during an on-going fault with dynamic cold load pick-up functions enabled, the timers of all non-directional overcurrent relay elements will be stopped, and may then be restarted based on their normal duration. During power up of the protective relay with an open circuit breaker, the time delay CB Open Time is started, and is processed using the "normal" settings. Therefore, when the circuit breaker is closed, the "normal" settings are effective. Figure 2-33 illustrates the timing sequence. Figure 2-34 shows the logic diagram of the dynamic cold load pickup feature. Figure 2-33 Timing charts of the dynamic cold load pickup function SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 118 2 Functions Figure 2-34 119 Logic diagram of the dynamic cold load pickup function (50c, 50Nc, 51c, 51Nc, 67c, 67Nc) SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.4 Dynamic Cold Load Pickup 2.4.2 Setting Notes General The dynamic cold load pickup function can only be enabled if address 117 Coldload Pickup was set to Enabled during configuration of the protective functions. If not required, this function should be set to Disabled. The function can be turned ON or OFF under address 1701 Coldload Pickup. Depending on the condition that should initiate the cold load pickup function address 1702 Start Condition is set to either No Current, Breaker Contact or to 79 ready. Naturally, the option Breaker Contact can only be selected if the device receives information regarding the switching state of the circuit breaker via at least one binary input. The option 79 ready modifies dynamically the pickup thresholds of the directional and non-directional time overcurrent protection when the automatic reclosing feature is ready. To initiate the cold load pickup the automatic reclosing function provides the internal signal "79M Auto Reclosing ready". It is always active when autoreclosure is available, activated, unblocked and ready for a further cycle (see also margin heading "Controlling Directional/Non-Directional Overcurrent Protection Elements via Cold Load Pickup" in Section 2.14.6). Time Delays There are no specific procedures on how to set the time delays at addresses 1703 CB Open Time, 1704 Active Time and 1705 Stop Time. These time delays must be based on the specific loading characteristics of the equipment being protected, and should be set to allow for brief overloads associated with dynamic cold load conditions. Non-Directional 50/51 Elements (Phases) The dynamic pickup values and time delays associated with non-directional time overcurrent protection are set at address block 18 (50C.../51C...) for phase currents: Non-Directional 50N/51N Elements (ground) Directional 67/67- TOC Elements (Phases) The dynamic pickup and delay settings for the 50N-2 element are set at addresses 1801 50c-2 PICKUP and 1802 50c-2 DELAY respectively; the dynamic pickup and delay settings for the 50N-1 element are set at addresses 1803 50c-1 PICKUP and 1804 50c-1 DELAY respectively; and the pickup, time multiplier (for IEC curves or user-defined curves), and time dial (for ANSI curves) settings for the 51N element are set at addresses 1805 51c PICKUP, 1806 51c TIME DIAL, and 1807 51c TIME DIAL, respectively. The dynamic pickup values and time delays associated with non-directional time overcurrent ground protection are set at address block 19 (50NC.../51NC...): The dynamic pickup and delay settings for the 50N-2 element are set at addresses 1901 50Nc-2 PICKUP and 1902 50Nc-2 DELAY respectively; the dynamic pickup and delay settings for the 50N-1 element are set at addresses 1903 50Nc-1 PICKUP and 1904 50Nc-1 DELAY respectively; and the pickup, time multiplier (for IEC curves or user-defined curves), and time dial (for ANSI curves) settings for the 51N element are set at addresses 1905 51Nc PICKUP, 1906 51Nc T-DIAL, and 1907 51Nc TDIAL, respectively. The dynamic pickup values and time delays associated with directional overcurrent phase protection are set at address block 20 (g67C...): The dynamic pickup and delay settings for the 67-2 element are set at addresses 2001 67c-2 PICKUP and 2002 67c-2 DELAY respectively; the dynamic pickup and delay settings for the 67-1 element are set at addresses 2003 67c-1 PICKUP and 2004 67c-1 DELAY respectively; and the pickup, time multiplier (for IEC curves or user-defined curves), and time dial (for ANSI curves) settings for the 67-TOC element SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 120 2 Functions are set at addresses 2005 67c-TOC PICKUP, 2006 67c-TOC T-DIAL , and 2007 67c-TOC T-DIAL respectively. Directional 67/67N Elements (ground) The dynamic pickup values and time delays associated with directional overcurrent ground protection are set at address block 21 (gU/AMZ E dynP.): The dynamic pickup and delay settings for the 67N-2 element are set at addresses 2101 67Nc-2 PICKUP and 2102 67Nc-2 DELAY respectively; the dynamic pickup and delay settings for the 67N-1 element are set at addresses 2103 67Nc-1 PICKUP and 2104 67Nc-1 DELAY respectively; and the pickup, time multiplier (for IEC curves or user-defined curves), and time dial (for ANSI curves) settings for the 67N-TOC element are set at addresses 2105 67Nc-TOC PICKUP, 2106 67Nc-TOC T-DIAL, 2107 67Nc-TOC T-DIAL, respectively. 2.4.3 Settings The table indicates region-specific default settings. Column C (configuration) indicates the corresponding secondary nominal current of the current transformer. Addr. Parameter C Setting Options Default Setting Comments 1701 COLDLOAD PICKUP OFF ON OFF Cold-Load-Pickup Function 1702 Start Condition No Current Breaker Contact 79 ready No Current Start Condition 1703 CB Open Time 0 .. 21600 sec 3600 sec Circuit Breaker OPEN Time 1704 Active Time 1 .. 21600 sec 3600 sec Active Time 1705 Stop Time 1 .. 600 sec; 600 sec Stop Time 1801 50c-2 PICKUP 1A 0.10 .. 35.00 A; 10.00 A 50c-2 Pickup 5A 0.50 .. 175.00 A; 50.00 A 0.00 .. 60.00 sec; 0.00 sec 50c-2 Time Delay 1A 0.10 .. 35.00 A; 2.00 A 50c-1 Pickup 5A 0.50 .. 175.00 A; 10.00 A 0.00 .. 60.00 sec; 0.30 sec 50c-1 Time Delay 1A 0.10 .. 4.00 A 1.50 A 51c Pickup 5A 0.50 .. 20.00 A 7.50 A 1802 50c-2 DELAY 1803 50c-1 PICKUP 1804 50c-1 DELAY 1805 51c PICKUP 1806 51c TIME DIAL 0.05 .. 3.20 sec; 0.50 sec 51c Time dial 1807 51c TIME DIAL 0.50 .. 15.00 ; 5.00 51c Time dial 1901 50Nc-2 PICKUP 1A 0.05 .. 35.00 A; 7.00 A 50Nc-2 Pickup 5A 0.25 .. 175.00 A; 35.00 A 0.00 .. 60.00 sec; 0.00 sec 50Nc-2 Time Delay 1A 0.05 .. 35.00 A; 1.50 A 50Nc-1 Pickup 5A 0.25 .. 175.00 A; 7.50 A 0.00 .. 60.00 sec; 0.30 sec 1902 50Nc-2 DELAY 1903 50Nc-1 PICKUP 1904 121 50Nc-1 DELAY 50Nc-1 Time Delay SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.4 Dynamic Cold Load Pickup Addr. 1905 Parameter 51Nc PICKUP C Setting Options Default Setting 1A 0.05 .. 4.00 A 1.00 A 5A 0.25 .. 20.00 A 5.00 A Comments 51Nc Pickup 1906 51Nc T-DIAL 0.05 .. 3.20 sec; 0.50 sec 51Nc Time Dial 1907 51Nc T-DIAL 0.50 .. 15.00 ; 5.00 51Nc Time Dial 2001 67c-2 PICKUP 1A 0.10 .. 35.00 A; 10.00 A 67c-2 Pickup 5A 0.50 .. 175.00 A; 50.00 A 0.00 .. 60.00 sec; 0.00 sec 67c-2 Time Delay 1A 0.10 .. 35.00 A; 2.00 A 67c-1 Pickup 5A 0.50 .. 175.00 A; 10.00 A 0.00 .. 60.00 sec; 0.30 sec 67c-1 Time Delay 1A 0.10 .. 4.00 A 1.50 A 67c Pickup 5A 0.50 .. 20.00 A 7.50 A 2002 67c-2 DELAY 2003 67c-1 PICKUP 2004 67c-1 DELAY 2005 67c-TOC PICKUP 2006 67c-TOC T-DIAL 0.05 .. 3.20 sec; 0.50 sec 67c Time Dial 2007 67c-TOC T-DIAL 0.50 .. 15.00 ; 5.00 67c Time Dial 2101 67Nc-2 PICKUP 1A 0.05 .. 35.00 A; 7.00 A 67Nc-2 Pickup 5A 0.25 .. 175.00 A; 35.00 A 0.00 .. 60.00 sec; 0.00 sec 67Nc-2 Time Delay 1A 0.05 .. 35.00 A; 1.50 A 67Nc-1 Pickup 5A 0.25 .. 175.00 A; 7.50 A 0.00 .. 60.00 sec; 0.30 sec 67Nc-1 Time Delay 1A 0.05 .. 4.00 A 1.00 A 67Nc-TOC Pickup 5A 0.25 .. 20.00 A 5.00 A 2102 67Nc-2 DELAY 2103 67Nc-1 PICKUP 2104 67Nc-1 DELAY 2105 67Nc-TOC PICKUP 2106 67Nc-TOC T-DIAL 0.05 .. 3.20 sec; 0.50 sec 67Nc-TOC Time Dial 2107 67Nc-TOC T-DIAL 0.50 .. 15.00 ; 5.00 67Nc-TOC Time Dial 2.4.4 Information List No. 1730 Information >BLOCK CLP Type of Information SP Comments >BLOCK Cold-Load-Pickup 1731 >BLK CLP stpTim SP >BLOCK Cold-Load-Pickup stop timer 1732 >ACTIVATE CLP SP >ACTIVATE Cold-Load-Pickup 1994 CLP OFF OUT Cold-Load-Pickup switched OFF 1995 CLP BLOCKED OUT Cold-Load-Pickup is BLOCKED 1996 CLP running OUT Cold-Load-Pickup is RUNNING 1997 Dyn set. ACTIVE OUT Dynamic settings are ACTIVE SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 122 2 Functions 2.5 Single-Phase Overcurrent Protection The single-phase overcurrent protection evaluates the current that is measured by the sensitive INS- or the normal IN input. Which transformer is used depends on the device version and the order number. Applications * Plain ground fault protection at a power transformer; * Sensitive tank leakage protection. 2.5.1 Functional Description The single-phase time overcurrent function yields the tripping characteristic depicted in Figure 2-35. Numerical algorithms filter the current to be detected. A particular narrow-band filter is used due to the possible high sensitivity. The current pickup thresholds and tripping times can be set. The detected current is compared to the pickup value 50 1Ph-1 PICKUP or 50 1Ph-2 PICKUP and reported if this is violated. The trip command is generated after the associated delay time 50 1Ph-1 DELAY or 50 1Ph-2 DELAY has elapsed. The two elements together form a two-stage protection. The dropout value is roughly equal to 95% of the pickup value for currents I > 0.3 * INom. The current filter is bypassed if currents are extremely high to achieve a short tripping time. This will always happen automatically when the instantaneous current value exceeds the setting value of the 50 1Ph-2 PICKUP element by at least factor 2 * 2. Figure 2-35 123 Two-stage characteristic of the single-phase time-overcurrent protection SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.5 Single-Phase Overcurrent Protection The following figure shows the logic diagram for the single-phase overcurrent protection. Figure 2-36 Logic diagram of the single-phase time-overcurrent protection SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 124 2 Functions 2.5.2 High-impedance Ground Fault Unit Protection Application Examples In the high-impedance procedure, all CT's operate at the limits of the protected zone parallel on a common, relatively high-resistive resistor R whose voltage is measured. The CTs must be of the same design and feature at least a separate core for high-impedance protection. In particular, they must have the same transformer ratios and approximately identical knee-point voltage. With 7SJ62/63/64, the high-impedance principle is particularly well suited for detecting ground faults in grounded networks at transformers, generators, motors and shunt reactors. Figure 2-37 shows an application example for a grounded transformer winding or a grounded motor/generator. The right-hand example depicts an ungrounded transformer winding or an ungrounded motor/generator where the grounding of the system is assumed somewhere else. Figure 2-37 Function of the High-Impedance Principle Ground fault protection according to the high-impedance principle The high-impedance principle is explained on the basis of a grounded transformer winding. No zero sequence current will flow during normal operation, i.e. the starpoint current is ISP = 0 and the phase currents are 3 I0 = IA + IB + IC = 0. With an external ground fault (Figure 2-38, left side), whose fault current is supplied via the grounded starpoint, the same current flows through the transformer starpoint and the phases. The corresponding secondary currents (all current transformers have the same transformation ratio) compensate each other; they are connected in series. Across resistor R only a small voltage is generated. It originates from the inner resistance of the transformers and the connecting cables of the transformers. Even if any current transformer experiences a partial saturation, it will become low-resistive for the period of saturation and creates a low-resistive shunt to the high-resistive resistor R. Thus, the high resistance of the resistor also has a restraining effect (the so-called resistance restraint). 125 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.5 Single-Phase Overcurrent Protection Figure 2-38 Principle of ground fault protection according to the high-impedance principle When a ground fault occurs in the protected zone (Figure 2-38 right), there is always a starpoint current ISP. The grounding conditions in the rest of the network determine how strong a zero sequence current from the system is. A secondary current which is equal to the total fault current tries to pass through the resistor R. Since the latter is high-resistive, a high voltage emerges immediately. Therefore, the current transformers get saturated. The RMS voltage across the resistor approximately corresponds to the knee-point voltage of the current transformers. Resistance R is dimensioned such that, even with the very lowest ground fault current to be detected, it generates a secondary voltage which is equal to the half knee-point voltage of current transformers (see also notes on dimensioning in Section 2.5.4). High-impedance Protection with 7SJ62/63/64 With 7SJ62/63/64 the sensitive measuring input INS or alternatively the insensitive measuring input IN is used for high-impedance protection. As this is a current input, the protection detects current through the resistor instead of the voltage across the resistor R. Figure 2-39 shows the connections diagram. The protection relay is connected in series to resistor R and measures its current. Varistor B limits the voltage when internal faults occur. High voltage peaks emerging with transformer saturation are cut by the varistor. At the same time, voltage is smoothed without reduction of the mean value. Figure 2-39 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 Connection diagram of the ground fault differential protection according to the high-impedance principle 126 2 Functions For protection against overvoltages it is also important that the device is directly connected to the grounded side of the current transformers so that the high voltage at the resistor can be kept away from the device. For generators, motors and shunt reactors high-impedance protection can be used analogously. All current transformers at the overvoltage side, the undervoltage side and the current transformer at the starpoint have to be connected in parallel when using auto-transformers. In principle, this scheme can be applied to every protected object. When applied as busbar protection, for example, the device is connected to the parallel connection of all feeder current transformers via the resistor. 2.5.3 Tank Leakage Protection Application Example The tank leakage protection has the task to detect ground leakage -- even high-resistive -- between a phase and the frame of a power transformer. The tank must be isolated from ground. A conductor links the tank to ground, and the current through this conductor is fed to a current input of the relay. When a tank leakage occurs, a fault current (tank leakage current) will flow through the grounding conductor to ground. This tank leakage current is detected by the single-phase overcurrent protection as an overcurrent; an instantaneous or delayed trip command is issued in order to disconnect all sides of the transformer A high-sensitivity single-phase current input is normally used for tank leakage protection. Figure 2-40 127 Principle of tank-leakage protection SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.5 Single-Phase Overcurrent Protection 2.5.4 Setting Notes General Single-phase time overcurrent protection can be set ON or OFF at address 2701 50 1Ph. The settings are based on the particular application. The setting ranges depend on whether the current measuring input is a sensitive or a normal input transformer (see also Ordering Information" in Appendix A.1). In case of a normal input transformer, set the pickup value for 50 1Ph-2 PICKUP in address 2702, the pickup value for 50 1Ph-1 PICKUP in address 2705. If only one element is required, set the one not required to . In case of a sensitive input transformer, set the pickup value for 50 1Ph-2 PICKUP in address 2703, the pickup value for 50 1Ph-1 PICKUP in address 2706. If only one element is required, set the one not required to . If you need a trip time delay for the 50-2 element, set it in address 2704 50 1Ph-2 DELAY, for the 50-1 element in address 2707 50 1Ph-1 DELAY. With setting 0 s no delay takes place. The selected times are additional time delays and do not include the operating time (measuring time, etc.) of the elements. The delay can also be set to ; the corresponding element will then not trip after pickup, but the pickup is reported. Special notes are given in the following for the use as high-impedance unit protection and tank leakage protection. Use as High-impedance Protection The use as high-impedance protection requires that starpoint current detection is possible in the system in addition to phase current detection (see example in figure 2-39). Furthermore, a sensitive input transformer must be available at device input IN/INS. In this case, only the pickup value for single-phase overcurrent protection is set at the 7SJ62/63/64 device for the current at input IN/INS. The entire function of high-impedance protection is, however, dependent on the interaction of current transformer characteristics, external resistor R and voltage across R. The following section gives information on this topic. Current Transformer Data for High-impedance Protection All current transformers must have an identical transformation ratio and nearly equal knee-point voltage. This is usually the case if they are of equal design and identical rated data. The knee-point voltage can be approximately calculated from the rated data of a CT as follows: VKPV Knee-point voltage RI Internal burden of the CT PNom Rated power of the CT INom Secondary nominal current of CT ALF Rated accuracy limit factor of the CT SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 128 2 Functions The rated current, rated power and accuracy limit factor are normally stated on the rating plate of the current transformer, e.g. Current transformer 800/5; 5P10; 30 VA That means INom = 5 A (from 800/5) ALF = 10 (from 5P10) PNom = 30 VA The internal burden is often stated in the test report of the current transformer. If not, it can be derived from a DC measurement on the secondary winding. Calculation Example: CT 800/5; 5P10; 30 VA with Ri = 0.3 or CT 800/1; 5P10; 30 VA with Ri = 5 Besides the CT data, the resistance of the longest connection lead between the CTs and the 7SJ62/63/64 device must be known. Stability with Highimpedance Protection The stability condition is based on the following simplified assumption: If there is an external fault, one of the current transformers gets totally saturated. The other ones will continue transmitting their (partial) currents. In theory, this is the most unfavorable case. Since, in practice, it is also the saturated transformer which supplies current, an automatic safety margin is guaranteed. Figure 2-41 shows a simplified equivalent circuit. CT1 and CT2 are assumed as ideal transformers with their inner resistances R i1 and R i2. Ra are the resistances of the connecting cables between current transformers and resistor R. They are multiplied by 2 as they have a forward and a return line. Ra2 is the resistance of the longest connecting cable. CT1 transmits current I1. CT2 shall be saturated. Because of saturation the transformer represents a low-resistance shunt which is illustrated by a dashed short-circuit line. R >> (2Ra2 + Ri2) is a further prerequisite. Figure 2-41 129 Simplified equivalent circuit of a circulating current system for high-impedance protection SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.5 Single-Phase Overcurrent Protection The voltage across R is then VR = I1 * ( 2Ra2 + Ri2 ) It is assumed that the pickup value of the 7SJ62/63/64 corresponds to half the kneepoint voltage of the current transformers. In the balanced case results VR = VKPV / 2 This results in a stability limit ISL , i.e. the maximum through-fault current below which the scheme remains stable: Calculation Example: For the 5-A CT as above with VKPV = 75 V and Ri = 0.3 longest CT connection lead 22 m (24.06 yd) with 4 mm2 cross-section; this corresponds to Ra = 0.1 that is 15 x rated current or 12 kA primary. For 1-A CT as above with VKPV = 350 V and Ri = 5 longest CT connection lead 107 m (117.02 yd) with 2.5 mm2 cross-section, results in Ra = 0.75 that is 27 x rated current or 21.6 kA primary. Sensitivity with High-impedance Protection The voltage present at the CT set is forwarded to the protective relay across a series resistor R as proportional current for evaluation. The following considerations are relevant for dimensioning the resistor: As already mentioned, it is desired that the high-impedance protection should pick up at half the knee-point voltage of the CT's. The resistor R can calculated on this basis. Since the device measures the current flowing through the resistor, resistor and measuring input of the device must be connected in series. Since, furthermore, the resistance shall be high-resistance (condition: R >> 2Ra2 + Ri2, as above mentioned), the inherent resistance of the measuring input can be neglected. The resistance is then calculated from the pickup current Ipu and the half knee-point voltage: SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 130 2 Functions Calculation Example: For 5-A CT as above desired pickup value Ipu = 0.1 A (equivalent to 16 A primary) For 1-A CT as above desired pickup value Ipu = 0.05 A (equivalent to 40 A primary) The required short-term power of the resistor is derived from the knee-point voltage and the resistance: As this power only appears during ground faults for a short period of time, the rated power can be smaller by approx. factor 5. Please bear in mind that when choosing a higher pickup value Ipu, the resistance must be decreased and, in doing so, power loss will increase significantly. The varistor B (see following figure) must be dimensioned such that it remains highresistive until reaching knee-point voltage, e.g. approx. 100 V for 5 A CT, approx. 500 V for 1 A CT. Figure 2-42 Connection diagram of the ground fault differential protection according to the high-impedance principle Even with an unfavorable external circuit, the maximum voltage peaks should not exceed 2 kV for safety reasons. 131 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.5 Single-Phase Overcurrent Protection If performance makes it necessary to switch several varistors in parallel, preference should by given to types with a flat characteristic to avoid asymmetrical loading. We therefore recommend the following types from METRSIL: 600A/S1/S256 (k = 450, = 0.25) 600A/S1/S1088 (k = 900, = 0.25) The pickup value (0.1 A or 0.05 A in the example) is set in address 2706 50 1Ph-1 PICKUP in the device. The 50-2 element is not required (address 2703 50 1Ph-2 PICKUP = ). The trip command of the element can be delayed in address 2707 50 1Ph-1 DELAY. This delay is normally set to 0. If a higher number of CT's is connected in parallel, e.g. as busbar protection with several feeders, the magnetizing currents of the transformers connected in parallel cannot be neglected any more. In this case, the magnetizing currents at the half kneepoint voltage (corresponds to the setting value) have to be summed up. These magnetizing currents reduce the current through the resistor R. Therefore the actual pickup value will be correspondingly higher. Use as Tank Leakage Protection The use as tank leakage protection requires that a sensitive input transformer is available at the device input IN/INS. In this case, only the pickup value for single phase overcurrent protection is set at the 7SJ62/63/64 device for the current at input IN/INS. The tank leakage protection is a sensitive overcurrent protection which detects the leakage current between the isolated transformer tank and ground. Its sensitivity is set in address 2706 50 1Ph-1 PICKUP. The 50-2 element is not required (address 2703 50 1Ph-2 PICKUP = ). The trip command of the element can be delayed in address 2707 50 1Ph-1 DELAY. It is normally set to 0. Note In the following Setting overview addresses 2703 and 2706 are valid for a highly sensitive current measuring input independently of the nominal current. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 132 2 Functions 2.5.5 Settings The table indicates region-specific default settings. Column C (configuration) indicates the corresponding secondary nominal current of the current transformer. Addr. Parameter 2701 50 1Ph 2702 50 1Ph-2 PICKUP C Setting Options Default Setting Comments OFF ON OFF 50 1Ph 1A 0.05 .. 35.00 A; 0.50 A 50 1Ph-2 Pickup 5A 0.25 .. 175.00 A; 2.50 A 2703 50 1Ph-2 PICKUP 0.003 .. 1.500 A; 0.300 A 50 1Ph-2 Pickup 2704 50 1Ph-2 DELAY 0.00 .. 60.00 sec; 0.10 sec 50 1Ph-2 Time Delay 2705 50 1Ph-1 PICKUP 1A 0.05 .. 35.00 A; 0.20 A 50 1Ph-1 Pickup 5A 0.25 .. 175.00 A; 1.00 A 2706 50 1Ph-1 PICKUP 0.003 .. 1.500 A; 0.100 A 50 1Ph-1 Pickup 2707 50 1Ph-1 DELAY 0.00 .. 60.00 sec; 0.50 sec 50 1Ph-1 Time Delay 2.5.6 Information List No. Information Type of Information Comments 5951 >BLK 50 1Ph SP >BLOCK 50 1Ph 5952 >BLK 50 1Ph-1 SP >BLOCK 50 1Ph-1 5953 >BLK 50 1Ph-2 SP >BLOCK 50 1Ph-2 5961 50 1Ph OFF OUT 50 1Ph is OFF 5962 50 1Ph BLOCKED OUT 50 1Ph is BLOCKED 5963 50 1Ph ACTIVE OUT 50 1Ph is ACTIVE 5966 50 1Ph-1 BLK OUT 50 1Ph-1 is BLOCKED 5967 50 1Ph-2 BLK OUT 50 1Ph-2 is BLOCKED 5971 50 1Ph Pickup OUT 50 1Ph picked up 5972 50 1Ph TRIP OUT 50 1Ph TRIP 5974 50 1Ph-1 PU OUT 50 1Ph-1 picked up 5975 50 1Ph-1 TRIP OUT 50 1Ph-1 TRIP 5977 50 1Ph-2 PU OUT 50 1Ph-2 picked up 5979 50 1Ph-2 TRIP OUT 50 1Ph-2 TRIP 5980 50 1Ph I: VI 50 1Ph: I at pick up 133 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.6 Voltage Protection 27, 59 2.6 Voltage Protection 27, 59 Voltage protection has the function to protect electrical equipment against undervoltage and overvoltage. Both operational states are unfavourable as overvoltage may cause, for example, insulation problems or undervoltage may cause stability problems. Applications * Abnormally high voltages often occur, e.g. in low loaded, long distance transmission lines, in islanded systems when generator voltage regulation fails, or after full load shutdown of a generator from the system. * The undervoltage protection function detects voltage collapses on transmission lines and electrical machines and prevents from inadmissible operating states and a possible loss of stability. 2.6.1 Measurement Principle Connection The voltages supplied to the device may correspond to the three phase-to-ground voltages VAN, VBN, VCN or two phase-to-phase voltages (VAB, VBC) and the displacement voltage (VN) or, in case of a single-phase connection, any phase-to-ground voltage or phase-to-phase voltage. Relay 7SJ64 provides the option to detect three phaseground voltages and the ground voltage in addition. With multiple-phase connection the connection mode was specified during the configuration in address 213 VT Connect. 3ph. If there is only one voltage transformer, the device has to be informed of this fact during configuration via address 240 VT Connect. 1ph (see also section 2.24). With three-phase connection, the overvoltage protection requires the phase-tophase voltages and, if necessary, calculated from the phase-to-ground voltages. In case of phase-to-phase connection, two voltages are measured and the third one is calculated. Depending on the configured parameter setting (address 614 OP. QUANTITY 59), the evaluation uses either the largest of the phase-to-phase voltages Vphph or the negative sequence component V2 of the voltages. With three-phase connection, undervoltage protection relies either on the positive sequence component V1 or the smallest of the phase-to-phase voltages Vphph. This is configured by setting the parameter value in address 615 OP. QUANTITY 27. The choice between phase-ground and phase-phase voltage allows voltage asymmetries (e.g. caused by a ground fault) to be taken into account (phase-ground) or to be unconsidered (phase-phase). With single-phase connection a phase-ground or phase-phase voltage is connected and evaluated (see also Section 2.24) dependent on the type of connection. Current Supervision The primary voltage transformers are arranged, depending on the system, either on the supply side or the load side of the associated circuit breaker. These different arrangements lead to different behavior of the voltage protection function when a fault occurs. When a tripping command is issued and a circuit breaker is opened, full voltage remains on the supply side while the load side voltage becomes zero. When voltage supply is absent, undervoltage protection, for instance, will remain picked up. If pickup condition must reset, the current can be used as an additional criterion for pickup of undervoltage protection (current supervision CS). Undervoltage pickup can only be maintained when the undervoltage criterion is satisfied and a settable SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 134 2 Functions minimum current level (BkrClosed I MIN) is exceeded. Here, the largest of the three phase currents is used. When the current decreases below the minimum current setting after the circuit breaker has opened, undervoltage protection will drop out. Note Note: If parameter CURRENT SUPERV. is set to disabled in address 5120, the device picks up when the undervoltage protection is enabled and no measured voltage is present and the undervoltage protection function is in pickup. Apply measuring voltage or block the voltage protection to continue with configuration. Moreover, you have the option of setting a flag via device operation for blocking the voltage protection. This initiates the reset of the pickup and device configuration can be resumed. Preparation of Measured Data 135 Using a Fourier analysis, the fundamental harmonic component of the three phase-tophase voltages is filtered out and forwarded for further processing. Depending on configuration, either the positive sequence component V1 of the voltages is supplied to the undervoltage protection elements (multiplied by 3 because the treshold values are set as phase-to-phase quantities) or the actual phase-to-phase voltage Vphph. The largest of the three phase-phase voltages iVphph is evaluated accordingly for overvoltage protection or the negative sequence voltage V2 is calculated, whereas in that case the thresholds should be set as phase-to-ground voltages. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.6 Voltage Protection 27, 59 2.6.2 Overvoltage Protection 59 Application The overvoltage protection has the task of protecting the transmission lines and electrical machines against inadmissible overvoltage conditions that may cause insulation damage. Abnormally high voltages often occur, e.g. on low loaded, long distance transmission lines, in islanded systems when generator voltage regulation fails, or after full load shutdown of a generator from the system. Function With three-phase connection, the fundamental component of the largest of the three phase-to-phase voltages is supplied to the overvoltage protection elements or, optionally, the negative sequence voltage. If only one voltage transformer is connected, the function is provided with the phaseto-ground or phase-phase fundamental component voltage in accordance with the connection type. The overvoltage protection has two elements. In case of a high overvoltage, tripping switchoff is performed with a short-time delay, whereas in case of less severe overvoltages, the switchoff is performed with a longer time delay. When one of the adjustable settings is exceeded, the 59 element picks up, and trips after an adjustable time delay elapses. The time delay is not dependent on the magnitude of the overvoltage. The dropout ratio for the two overvoltage elements (= Vdropout value/Vpickup value) can be set. The following figure shows the logic diagram of the overvoltage protection for phase- phase voltages. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 136 2 Functions Figure 2-43 2.6.3 Logic diagram of the overvoltage protection Undervoltage Protection 27 Application The undervoltage protection function detects voltage collapses on transmission lines and electrical machines and prevents the persistance of inadmissible operating states and a possible loss of stability. Function With three-phase connection, undervoltage protection uses the positive sequence fundamental component or, optionally, also the actual phase-to-phase voltages. The latter case applies the smallest of the phase-to-phase voltages. If only one voltage transformer is connected, the function is provided with the phaseto-ground or phase-phase fundamental component voltage in accordance with the type of connection. Undervoltage protection consists of two definite time elements (27-1 PICKUP and 27-2 PICKUP). Therefore, tripping can be time-graded depending on how severe voltage collapses are. Voltage thresholds and time delays can be set individually for both elements. The voltage limit values are configured as phase-to-phase quantities. Thus, either the positive sequence system value V1 * 3 or, optionally, the smallest of the phase-to-phase voltages is evaluated. The dropout ratio for the two undervoltage elements (= Vdropout value/Vpickup value) can be set. 137 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.6 Voltage Protection 27, 59 The undervoltage protection works in an additional frequency range. This ensures that the protective function is preserved even when it is applied, e.g. as motor protection in context with decelerating motors. However, the r.m.s. value of the positive-sequence voltage component is considered too small when severe frequency deviations exist. This function therefore exhibits an overfunction. If applications are anticipated in which the frequency range of fNom 10%, will be exceeded, the current criterion will not return a correct result and must be switched off. Figure 2-44 shows a typical voltage profile during a fault for source side connection of the voltage transformers. Because full voltage is present after the circuit breaker is opened the current supervision CS described above is not necessary in this case. After the voltage drops below the pickup setting, tripping is initiated after time delay 27-1 DELAY. As long as the voltage remains below the drop out setting, reclosing is blocked. Only after the fault has been cleared, i.e. when the voltage increases above the drop out level, the element drops out and allows reclosing of the circuit breaker. Figure 2-44 Typical fault profile for source side connection of the voltage transformer (without current supervision) Figure 2-45 shows a fault profile for a load side connection of the voltage transformers. When the circuit breaker is open, the voltage disappears (the voltage remains below the pickup setting), and current supervision is used to ensure that pickup drops out after the circuit breaker has opened (BkrClosed I MIN). After the voltage drops below the pickup setting, tripping is initiated after time delay 27-1 DELAY. When the circuit breaker opens voltage decreases to zero and undervoltage pickup is maintained. The current value also decreases to zero so that current supervision is reset as soon as the release threshold (BkrClosed I MIN) is exceeded. Thanks to the AND-combination of voltage and current criteria pickup of the protective function is also reset. As a consequence, energization is admitted a new when the minimum command time elapsed. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 138 2 Functions Figure 2-45 Typical fault profile for load side connection of the voltage transformers (with current supervision) Following closing of the circuit breaker, current supervision BkrClosed I MIN is delayed for a short period of time. If voltage criterion drops out during this time period (about 60 ms), the protection function will not pick up. Thereby no fault record is generated when closing the CB in a healthy system. It is important to understand, however, that if a low voltage condition exists on the load after the circuit breaker is closed (unlike Figure 2-45), the desired pickup of the element will be delayed by 60 ms. 139 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.6 Voltage Protection 27, 59 The following figure shows the logic diagram for the undervoltage protection function. Figure 2-46 Logic diagram of the undervoltage protection SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 140 2 Functions 2.6.4 Setting Notes General Voltage protection is only in effect and accessible if address 150 27/59 is set to Enabled during configuration of protective functions. If the fuction is not required, Disabled is set. The setting values refer to phase-phase voltages with three-phase voltage transformer connection and also with connection of only one phase-phase voltage if the evaluation quantity for overvoltage protection was configured to phase-phase voltage at address 614 OP. QUANTITY 59. They must be set as phase-to-ground voltages if this parameter is configured to negative-sequence voltage V2. In case of a single-phase connection of a phase-to-ground voltage, the threshold values must be set as phase-to-ground voltages. The setting ranges depend on the type of voltage transformer connection utilized (specified at address 213 VT Connect. 3ph, three phase-to-ground voltages or two phase-to-phase voltages). For voltage transformers connected in a ground-wye configuration, higher setting values may be used because the voltage inputs are subjected only to phase-to-ground voltage levels. Overvoltage protection can be turned ON or OFF, or set to Alarm Only at address 5001 FCT 59. Undervoltage protection can be turned ON, OFF, or Alarm Only at address 5101 FCT 27. With the protection functions activated (ON), tripping, the opening of a fault and fault recording are initiated when the thresholds are exceeded and the set time delays have expired. With setting Alarm Only no trip command is given, no fault is recorded and no spontaneous fault annunciation is shown on the display. Overvoltage Protection with Phase Voltages The largest of the voltages applied is evaluated for the phase-to-phase or phase-toground overvoltage protection. With three-phase connection as well as with singlephase connection of a phase-to-phase voltage the threshold is set as a phase-tophase quantity. With single phase-to-ground connection the threshold is set as phase- to-ground voltage. Overvoltage protection includes two elements. The pickup value of the lower threshold is set at address 5002 or 5003, 59-1 PICKUP (depending on if the phase-to-ground or the phase-to-phase voltages are connected), while time delay is set at address 5004, 59-1 DELAY (a longer time delay ). The pickup value of the upper element is set at address 5005 or 5006, 59-2 PICKUP, while the time delay is set at address 5007,59-2 DELAY (a short time delay). There are no clear cut procedures on how to set the pickup values. However, since the overvoltage function is primarily intended to prevent insulation damage on equipment and users, the setting value 5002 or 5003 59-1 PICKUP should be set between 110% and 115% of nominal voltage, and setting value 5005 or 5006 59-2 PICKUP should be set to about 130% of nominal voltage. Addresses 5002 and 5005 can be accessed if phase-to-ground voltages are connected to 7SJ62/63/64, whereas addresses 5003 and 5006 can be accessed if phase-tophase voltages are connected. The time delays of the overvoltage elements are entered at addresses 5004 59-1 DELAY and 5007 59-2 DELAY and should be selected to allow the brief voltage spikes that are generated during switching operations and to enable clearance of stationary overvoltages in time. 141 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.6 Voltage Protection 27, 59 Overvoltage Protection - Negative Sequence System V2 The three-phase voltage transformer connection for the overvoltage protection can be configured by means of parameter 614 OP. QUANTITY 59. Either the largest of the phase-to-phase voltages (Vphph) or the negative system voltage (V2) are evaluated as measured quantities. The negative system detects negative sequence reactance and can be used for the stabilization of the time overcurrent protection. With backup protection of transformers or generators, the fault currents lie, in some cases, only slightly over the load currents. To obtain a pickup threshold of the definite time overcurrent protection which should be as sensitive as possible, it is necessary to stabilize the definite time overcurrent protection by the voltage protection. Overvoltage protection includes two elements. Thus, with configuration of the negative system, a longer time delay (address 5004, 59-1 DELAY) may be assigned to the lower element (address 5015, 59-1 PICKUP V2) and a shorter time delay (address 5007, 59-2 DELAY) may be assigned to the upper element (address 5016, 59-2 PICKUP V2). There are no clear cut procedures on how to set the pickup values 591 PICKUP V2 or 59-2 PICKUP V2, as they depend on the respective station configuration. Since the negative sequence voltage V2 corresponds to a phase-ground voltage, their threshold value must be set as such. The parameter 5002 59-1 PICKUP and 5005 59-2 PICKUP or 5003 59-1 PICKUP and 5006 59-2 PICKUP are deleted during configuration of the negative sequence voltage and the setting values are activated under the addresses 5015 59-1 PICKUP V2 or 5016 59-2 PICKUP V2. Be aware that the parameter device 614 OP. QUANTITY 59 is ignored with single-pole voltage transformer connection and the activation of the threshold value for the phase-to-phase voltages takes place. The time delays of the overvoltage elements are entered at addresses 5004 59-1 DELAY and 5007 59-2 DELAY and should be selected to allow the brief voltage spikes that are generated during switching operations and to enable clearance of stationary overvoltages in time. Dropout Threshold of the Overvoltage Protection The dropout thresholds of the 59-1 element and the 59-2 element can be set via the dropout ratio r = Vdropout/Vpickup (5117 59-1 DOUT RATIO or 5118 59-2 DOUT RATIO). In this, the following marginal condition always holds for r: r * (configured pickup threshold ) 150 V with connection of phase-to-phase voltages or r * (configured pickup threshold ) 260 V with connection of phase-to-ground voltages. The minimum hysteresis is 0.6 V. Undervoltage Protection - Positive Sequence System V1 The positive sequence component (V1) is evaluated for the undervoltage protection. Especially in case of stability problems, their acquisition is advantageous because the positive sequence system is relevant for the limit of the stable energy transmission. Concerning the pickup values, there are not clear cut procedures on how to set them. However, because the undervoltage protection function is primarily intended to protect induction machines from voltage dips and to prevent stability problems, the pickup values will usually be between 60% and 85% of the nominal voltage. Please note that with frequency deviations of > 5 Hz of the calculated r. m. s value of the voltage will be too small and the device will perform unwanted operations. With a three-phase connection and a single-phase connection of a phase-to-phase voltage the thresholds are set as phase-phase quantities. Since the positive sequence component of the voltages corresponds to a phase-ground voltage, their threshold value has to be multiplied with 3. With a single-phase phase-to-ground connection the threshold is set as phase-ground voltage. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 142 2 Functions The time delay settings should be set that tripping results when voltage dips occur, which could lead to unstable operating conditions. On the other hand, the time delay should be long enough to avoid tripping due to momentary voltage dips. Undervoltage protection includes two definite time elements. The pickup value of the lower threshold is set at address 5110 or 5111, 27-2 PICKUP (depending on the voltage transformer connection, phase-to-ground or phase-to-phase), while time delay is set at address 5112, 27-2 DELAY (short time delay). The pickup value of the upper element is set at address 5102 or 5103, 27-1 PICKUP, while the time delay is set at address 5106, 27-1 DELAY (a somewhat longer time delay). Setting these elements in this matter allows the undervoltage protection function to closely follow the stability behaviour of the system. Undervoltage Protection with Phase Voltages The smallest of the phase-to-phase voltages Vphph can also be configured as measured quantity for the undervoltage protection with three-phase connection by means of parameter 615 OP. QUANTITY 27 instead of the positive sequence component (V1). The threshold values have to be set as phase-phase quantities. The time delay settings should be set that tripping results when voltage dips occur which could lead to unstable operating conditions. On the other hand, the time delay should be long enough to permissable short voltage dips. Undervoltage protection includes two definite time elements. The pickup value of the lower threshold is set at address 5110 or 5111, 27-2 PICKUP (depending on the voltage transformer connection, phase-to-ground or phase-to-phase), while time delay is set at address 5112, 27-2 DELAY (short time delay). The pickup value of the upper element is set at address 5102 or 5103, 27-1 PICKUP, while the time delay is set at address 5106, 27-1 DELAY (a somewhat longer time delay). Setting these elements in this matter allows the undervoltage protection function to closely follow the stability behaviour of the system. Dropout Threshold of the Undervoltage Protection The dropout thresholds of the 27-1 element and the 27-2 element can be set via the dropout ratio r = Vdropout/Vpickup (5113 27-1 DOUT RATIO or 5114 27-2 DOUT RATIO). In this, the following marginal condition always holds for r: r * (configured pickup threshold ) 120 V with connection of phase-to-phase voltages or r * (configured pickup threshold ) 210 V with connection of phase-to-ground voltages. The minimum hysteresis is 0.6 V. Note If a setting is selected such that the dropout threshold (= pickup threshold * dropout ratio) results in a greater value than 120 V / 210 V, it will be limited automatically. No error message occurs. Current Criterion for Undervoltage Protection 143 The 27-2 and 27-1 elements can be supervised by the current flow monitoring setting. If the CURRENT SUPERV. is switched ON at address 5120 (factory setting), the release condition of the current criterion must be fulfilled in addition to the corresponding undervoltage condition, which means that a configured minimum current (BkrClosed I MIN, address 212) must be present to make sure that this protective function can pick up. Therefore, it is possible to achieve that pickup of undervoltage protection drops out when the line is disconnected from voltage supply. Furthermore, SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.6 Voltage Protection 27, 59 this feature prevents an immediate general pickup of the device when the device is powered-up without measurement voltage being present. Note If parameter CURRENT SUPERV. is set to disabled in address 5120, the device picks up without measurement voltage and the undervoltage protection function in pickup. Further configuration can be performed by pickup of measurement voltage or blocking voltage protection. The latter can be initiated via device operation in DIGSI and via communication from the control centre by means of a tagging command for blocking voltage protection. This causes the dropout of the pickup and parameterization can be resumed. Please note that pickup threshold BkrClosed I MIN is used in other protective functions as well, including breaker failure protection, overload protection, and start inhibit for motors. 2.6.5 Settings Addresses which have an appended "A" can only be changed with DIGSI, under "Display Additional Settings". Addr. Parameter Setting Options Default Setting Comments 5001 FCT 59 OFF ON Alarm Only OFF 59 Overvoltage Protection 5002 59-1 PICKUP 40 .. 260 V 110 V 59-1 Pickup 5003 59-1 PICKUP 40 .. 150 V 110 V 59-1 Pickup 5004 59-1 DELAY 0.00 .. 100.00 sec; 0.50 sec 59-1 Time Delay 5005 59-2 PICKUP 40 .. 260 V 120 V 59-2 Pickup 5006 59-2 PICKUP 40 .. 150 V 120 V 59-2 Pickup 5007 59-2 DELAY 0.00 .. 100.00 sec; 0.50 sec 59-2 Time Delay 5015 59-1 PICKUP V2 2 .. 150 V 30 V 59-1 Pickup V2 5016 59-2 PICKUP V2 2 .. 150 V 50 V 59-2 Pickup V2 5017A 59-1 DOUT RATIO 0.90 .. 0.99 0.95 59-1 Dropout Ratio 5018A 59-2 DOUT RATIO 0.90 .. 0.99 0.95 59-2 Dropout Ratio 5101 FCT 27 OFF ON Alarm Only OFF 27 Undervoltage Protection 5102 27-1 PICKUP 10 .. 210 V 75 V 27-1 Pickup 5103 27-1 PICKUP 10 .. 120 V 75 V 27-1 Pickup 5106 27-1 DELAY 0.00 .. 100.00 sec; 1.50 sec 27-1 Time Delay 5110 27-2 PICKUP 10 .. 210 V 70 V 27-2 Pickup 5111 27-2 PICKUP 10 .. 120 V 70 V 27-2 Pickup 5112 27-2 DELAY 0.00 .. 100.00 sec; 0.50 sec 27-2 Time Delay SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 144 2 Functions Addr. Parameter Setting Options Default Setting Comments 5113A 27-1 DOUT RATIO 1.01 .. 3.00 1.20 27-1 Dropout Ratio 5114A 27-2 DOUT RATIO 1.01 .. 3.00 1.20 27-2 Dropout Ratio 5120A CURRENT SUPERV. OFF ON ON Current Supervision 2.6.6 Information List No. Information Type of Information Comments 234.2100 27, 59 blk IntSP 27, 59 blocked via operation 6503 SP >BLOCK 27 undervoltage protection >BLOCK 27 6505 >27 I SUPRVSN SP >27-Switch current supervision ON 6506 >BLOCK 27-1 SP >BLOCK 27-1 Undervoltage protection 6508 >BLOCK 27-2 SP >BLOCK 27-2 Undervoltage protection 6513 >BLOCK 59-1 SP >BLOCK 59-1 overvoltage protection 6530 27 OFF OUT 27 Undervoltage protection switched OFF 6531 27 BLOCKED OUT 27 Undervoltage protection is BLOCKED 6532 27 ACTIVE OUT 27 Undervoltage protection is ACTIVE 6533 27-1 picked up OUT 27-1 Undervoltage picked up 6534 27-1 PU CS OUT 27-1 Undervoltage PICKUP w/curr. superv 6537 27-2 picked up OUT 27-2 Undervoltage picked up 6538 27-2 PU CS OUT 27-2 Undervoltage PICKUP w/curr. superv 6539 27-1 TRIP OUT 27-1 Undervoltage TRIP 6540 27-2 TRIP OUT 27-2 Undervoltage TRIP 6565 59 OFF OUT 59-Overvoltage protection switched OFF 6566 59 BLOCKED OUT 59-Overvoltage protection is BLOCKED 6567 59 ACTIVE OUT 59-Overvoltage protection is ACTIVE 6568 59-1 picked up OUT 59 picked up 6570 59-1 TRIP OUT 59 TRIP 6571 59-2 picked up OUT 59-2 Overvoltage V>> picked up 6573 59-2 TRIP OUT 59-2 Overvoltage V>> TRIP 145 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.7 Negative Sequence Protection 46 2.7 Negative Sequence Protection 46 Negative sequence protection detects unbalanced loads on the system. Applications * The application of negative sequence protection to motors has a special significance. Unbalanced loads create counter-rotating fields in three-phase induction motors, which act on the rotor at double frequency. Eddy currents are induced on the rotor surface, which causes local overheating in rotor end zones and the slot wedges. This especially goes for motors which are tripped via vacuum contactors with fuses connected in series. With single phasing due to operation of a fuse, the motor only generates small and pulsing torques such that it soon is thermally strained assuming that the torque required by the machine remains unchanged. In addition, the unbalanced supply voltage introduces the risk of thermal overload. Due to the small negative sequence reactance even small voltage asymmetries lead to large negative sequence currents. * In addition, this protection function may be used to detect interruptions, faults, and polarity problems with current transformers. * It is also useful in detecting 1 pole and 2 pole faults with fault current lower than the maximum load current. Prerequisites 2.7.1 In order to prevent pickup chattering, the negative sequence protection becomes only active when one phase current becomes larger than 0.1 x INom and all phase currents are smaller than 4 x INom. Definite Time element 46-1, 46-2 The definite time characteristic consists of two elements. As soon as the first settable threshold 46-1 PICKUP is reached, a pickup message is output and time element 46-1 DELAY is started. When the second element 46-2 PICKUP is started, another message is output and time element 46-2 DELAY is initiated. Once either time delay elapses, a trip signal is initiated. Figure 2-47 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 Definite time characteristic for negative sequence protection 146 2 Functions Settable Dropout Times 2.7.2 Pickup stabilization for the definite-time tripping characteristic 46-1, 46-2 can be accomplished by means of settable dropout times. This facility is used in power systems with intermittent faults. Used together with electromechanical relays, it allows different dropout profiles to be adapted and time grading of digital and electromechanical components. Inverse Time element 46-TOC The inverse time element is dependent on the ordered device version. It operates with IEC or ANSI characteristic tripping curves. The characteristics and associated formulas are given in the Technical Data. When programming the inverse time characteristic 46-TOC, also definite time elements 46-2 PICKUP and 46-1 PICKUP are available (see previous section). Pickup and Tripping The negative sequence current I2 is compared with setting value 46-TOC PICKUP. When negative sequence current exceeds 1.1 times the setting value, a pickup annunciation is generated. The tripping time is calculated from the negative sequence current according to the characteristic selected. After expiration of the time period a tripping command is output. The characteristic curve is illustrated in the following Figure. Figure 2-48 Inverse time characteristic for negative sequence protection Drop Out for IEC Curves The element drops out when the negative sequence current decreases to approx. 95% of the pickup setting. The time delay resets immediately in anticipation of another pickup. Drop Out for ANSI Curves When using an ANSI curve, select if dropout after pickup is instantaneous or with disk emulation. "Instantaneous" means that pickup drops out when the pickup value of approx. 95 % is undershot. For a new pickup the time delay starts at zero. 147 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.7 Negative Sequence Protection 46 The disk emulation evokes a dropout process (timer counter is decremented) which begins after de-energization. This process corresponds to the reset rotation of a Ferraris-disk (explaining its denomination "disk emulation"). In case several faults occur successively the "history" is taken into consideration due to the inertia of the Ferrarisdisk and the timing response is correspondingly adapted. This ensures a proper simulation of the temperature rise of the protected object even for extremely fluctuating unbalanced load values. Reset begins as soon as 90 % of the setting value is undershot, in correspondence with the dropout curve of the selected characteristic. In the range between the dropout value (95 % of the pickup value) and 90 % of the setting value, the incrementing and the decrementing processes are in idle state. Disk emulation offers advantages when the behaviour of the negative sequence protection must be coordinated with other relays in the system based on electromagnetic measuring principles. Logic The following figure shows the logic diagram for the negative sequence protection function. The protection may be blocked via a binary input. This resets pickup and time stages and clears measured values. When the negative sequence protection operating range is left (i.e. all phase currents below 0.1 x INom or at least one phase current is greater than 4 x INom), all pickups issued by the negative sequence protection function are reset. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 148 2 Functions Figure 2-49 Logic diagram of the unbalanced load protection Pickup of the definite time elements can be stabilized by setting the dropout time 4012 46 T DROP-OUT. This time is started if the current falls below the threshold and maintains the pickup condition. The function thus does not drop out instantaneously. The trip delay time continues in the meantime. After the dropout delay time has elapsed, the pickup is reported OFF and the trip delay time is reset unless the threshold has been violated again. If the threshold is violated again while the dropout delay time is still running, it will be cancelled. The trip delay time continues however. If the threshold is still exceeded after the time has elapsed, a trip will be initiated immediately. If the threshold violation then no longer exists, there will be no response. If the threshold is violated again after the trip command delay time has elapsed and while the dropout delay time is still running, a trip will be initiated at once. 149 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.7 Negative Sequence Protection 46 The settable dropout times do not affect the trip times of the inverse time elements since they depend dynamically on the measured current value. Disk emulation is applied here to coordinate the dropout behavior with the electromechanical relays. 2.7.3 Setting Notes General Negative sequence protection 46 is configured at address 140, (see Section 2.1.1.2). If only the definite time elements are desired, address 46 should be set to Definite Time. Selecting 46 = TOC IEC or = TOC ANSI in address 140 will additionally make all the parameters relevant for inverse characteristics available. If the function is not required Disabled is set. The function can be turned ON or OFF in address 4001 FCT 46. The default pickup settings and delay settings are generally sufficient for most applications. If data is available from the manufacturer regarding the permissable continous load imbalance and the permissable level of load imbalance per unit of time, then this data should preferably be used. It is important to relate the manufacturer's data to the primary values of the machine, for example, the maximum permissible continuous inverse current related to the nominal machine current. For the settings on the protective relay, this information is converted to the secondary inverse current. The following applies with Definite Time Elements I2 perm prim Permissible Thermal Inverse Current of the Motor INom Motor Nominal Motor Current ICT sec Secondary Nominal Current of the Current Transformer ICT prim Primary Nominal Current of the Current Transformer The unbalanced load protection function is composed of two elements. Therefore, the upper element (address 4004 46-2 PICKUP) can be set to a short time delay 4005 46-2 DELAY) and the lower element (address 4002 46-1 PICKUP) can be set to a somewhat longer time delay (address 4003 46-1 DELAY). This allows the lower element to act e.g. as an alarm while the upper element will cut the inverse characteristic as soon as high inverse currents are present. If 46-2 PICKUP is set to about 60 %, tripping is always performed with the thermal characteristic. On the other hand, with more than 60% of unbalanced load, a two-phase fault can be assumed. The delay time 46-2 DELAY must be coordinated with the system grading of phase-tophase faults. If power supply with current I is provided via just two phases, the following applies to the inverse current: SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 150 2 Functions Examples: Motor with the following data: Nominal current INom Motor = 545 A Continuously permissible neg- I2 dd prim /INom Motor = 0.11 continuous ative sequence current Briefly permissible negative sequence current I2 long-term prim /INom Motor= 0.55 for T max = 1 s Current Transformer CT = 600 A / 1 A Setting value I2> = 0.11 * 545 A * (1/600 A) = 0.10 A Setting value I2> = 0.55 * 545 A * (1/600 A) = 0.50 A When protecting feeder or cable systems, unbalanced load protection may serve to identify low magnitude unsymmetrical faults below the pickup values of the directional and non-directional overcurrent elements. Here, the following must be observed: A phase-to-ground fault with current I corresponds to the following negative sequence current: On the other hand, with more than 60% of unbalanced load, a phase-to-phase fault can be assumed. The delay time 46-2 DELAY must be coordinated with the system grading of phase-to-phase faults. For a power transformer, unbalanced load protection may be used as sensitive protection for low magnitude phase-to-ground and phase-to-phase faults. In particular, this application is well suited for delta-wye transformers where low side phase-toground faults do not generate high side zero sequence currents (e.g. vector group Dy). Since transformers transform symmetrical currents according to the transformation ratio "CTR", the relationship between negative sequence currents and total fault current for phase-to-phase faults and phase-to-ground faults are valid for the transformer as long as the turns ratio "CTR" is taken into consideration. Consider a transformer with the following data: 151 Base Transformer Rating SNomT = 16 MVA Primary Nominal Voltage VNom = 110 kV Secondary Nominal Voltage VNom = 20 kV Vector Groups Dy5 High Side CT 100 A / 1 A (TRV = 110/20) (CTI = 100) SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.7 Negative Sequence Protection 46 The following fault currents may be detected at the low side: If 46-1 PICKUP on the high side of the device is set to = 0.1 A, then a fault current of I = 3 * TRV * TRI * 46-1 PICKUP = 3 * 110/20 * 100 * 0.1 A = 165 A for single-phase faults and 3 * TRV * TRI *46-1 PICKUP = 95 A can be detected for two-phase faults at the low side. This corresponds to 36 % and 20 % of the transformer nominal current respectively. It is important to note that load current is not taken into account in this simplified example. As it cannot be recognized reliably on which side the thus detected fault is located, the delay time 46-1 DELAY must be coordinated with other downstream relays in the system. Pickup Stabilization (Definite Time) Pickup of the definite time elements can be stabilized by means of a configurable dropout time. This dropout time is set in 4012 46 T DROP-OUT. IEC Curves (Inverse Time Tripping Curve) The thermal behavior of a machine can be closely replicated due to negative sequence by means of an inverse time tripping curve. In address 4006 46 IEC CURVE, select out of three IEC curves provided by the device the curve which is most similar to the thermal unbalanced load curve provided by the manufacturer. The tripping curves of the protective relay, and the formulas on which they are based, are given in the Technical Data. It must be noted that a safety factor of about 1.1 has already been included between the pickup value and the setting value when an inverse time characteristic is selected. This means that a pickup will only occur if an unbalanced load of about 1.1 times the setting value 46-TOC PICKUP is present (address 4008). The dropout is performed as soon as the value falls below 95% of the pickup value. The associated time multiplier is entered at address 4010, 46-TOC TIMEDIAL. The time multiplier can also be set to . After pickup the element will then not trip. Pickup, however, will be signaled. If the inverse time element is not required at all, address 140 46 should be set to Definite Time during the configuration of protective functions (Section 2.1.1.2). ANSI Curves (Inverse Time Tripping Curve) Behavior of a machine due to negative sequence current can be closely replicated by means of an inverse time tripping curve. In address 4007 the 46 ANSI CURVE, select out of four ANSI curves provided by the device the curve which is most similar to the thermal unbalanced load curve provided by the manufacturer. The tripping curves of the protective relay, and the formulas on which they are based, are given in the Technical Data. It must be noted that a safety factor of about 1.1 has already been included between the pickup value and the setting value when an inverse time characteristic is selected. This means that a pickup will only occur if an unbalanced load of about 1.1 times the setting value is present. If Disk Emulation was selected at address 4011 46-TOC RESET, reset will occur in accordance with the reset curve as described in the Functional Description. The unbalanced load value is set at address 4008 46-TOC PICKUP. The corresponding time multiplier is accessible via address 4009 46-TOC TIMEDIAL. The time multiplier can also be set to . After pickup the element will then not trip. Pickup, however, will be signaled. If the inverse time element is not required at all, address 140 46 should be set to Definite Time during the configuration of protective functions (Section 2.1.1.2). SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 152 2 Functions 2.7.4 Settings Addresses which have an appended "A" can only be changed with DIGSI, under "Display Additional Settings". The table indicates region-specific default settings. Column C (configuration) indicates the corresponding secondary nominal current of the current transformer. Addr. Parameter 4001 FCT 46 4002 46-1 PICKUP 4003 46-1 DELAY 4004 46-2 PICKUP C Setting Options Default Setting Comments OFF ON OFF 46 Negative Sequence Protection 1A 0.10 .. 3.00 A 0.10 A 46-1 Pickup 5A 0.50 .. 15.00 A 0.50 A 0.00 .. 60.00 sec; 1.50 sec 46-1 Time Delay 1A 0.10 .. 3.00 A 0.50 A 46-2 Pickup 5A 0.50 .. 15.00 A 2.50 A 4005 46-2 DELAY 0.00 .. 60.00 sec; 1.50 sec 46-2 Time Delay 4006 46 IEC CURVE Normal Inverse Very Inverse Extremely Inv. Extremely Inv. IEC Curve 4007 46 ANSI CURVE Extremely Inv. Inverse Moderately Inv. Very Inverse Extremely Inv. ANSI Curve 4008 46-TOC PICKUP 1A 0.10 .. 2.00 A 0.90 A 46-TOC Pickup 5A 0.50 .. 10.00 A 4.50 A 4009 46-TOC TIMEDIAL 0.50 .. 15.00 ; 5.00 46-TOC Time Dial 4010 46-TOC TIMEDIAL 0.05 .. 3.20 sec; 0.50 sec 46-TOC Time Dial 4011 46-TOC RESET Instantaneous Disk Emulation Instantaneous 46-TOC Drop Out 4012A 46 T DROP-OUT 0.00 .. 60.00 sec 0.00 sec 46 Drop-Out Time Delay 2.7.5 Information List No. Information Type of Information Comments 5143 >BLOCK 46 SP >BLOCK 46 5151 46 OFF OUT 46 switched OFF 5152 46 BLOCKED OUT 46 is BLOCKED 5153 46 ACTIVE OUT 46 is ACTIVE 5159 46-2 picked up OUT 46-2 picked up 5165 46-1 picked up OUT 46-1 picked up 5166 46-TOC pickedup OUT 46-TOC picked up 5170 46 TRIP OUT 46 TRIP 5171 46 Dsk pickedup OUT 46 Disk emulation picked up 153 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.8 Motor Protection (Motor Starting Protection 48, Motor Restart Inhibit 66) 2.8 Motor Protection (Motor Starting Protection 48, Motor Restart Inhibit 66) For protection of motors the devices 7SJ62/63/64 are provided with a motor starting time monitoring feature and a restart inhibit. The first feature mentioned supplements the overload protection (see Section 2.10) by protecting the motor from frequent starting or extended starting durations. The restart inhibit described prevents from a restart of the motor, when starting might exceed the permissible time the rotor can suffer heating. 2.8.1 Motor Starting Protection 48 By application of devices 7SJ62/63/64 to motors, the motor starting time monitoring protects the motor from too long starting attempts and supplements the overload protection (see Section 2.10) 2.8.1.1 Description General In particular, rotor-critical high-voltage motors can quickly be heated above their thermal limits when multiple starting attempts occur in a short period of time. If the durations of these starting attempts are lengthened e.g. by excessive voltage dips during motor starting, by excessive load torques, or by blocked rotor conditions, a tripping signal will be initiated by the device. Motor starting is detected when a settable current threshold I MOTOR START is exceeded. Calculation of the tripping time is then initiated. The protection function consists of one definite time and one inverse time tripping element. Inverse Time Overcurrent Element The inverse time overcurrent element is designed to operate only when the rotor is not blocked. With decreased starting current resulting from voltage dips when starting the motor, prolonged starting times are evaluated correctly and tripping with appropriate time delay. The tripping time is calculated based on the following equation: with tTRIP - Actual tripping time for flowing current I tSTARTUPmax - Tripping time for nominal start-up current IA (address 4103, STARTUP TIME) I - Current actually flowing (measurement value) ISTARTUP - Nominal starting current of the motor (address 4102, STARTUP CURRENT) IMOTOR START - Pickup value for recognition of motor starting (address 1107I MOTOR START), SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 154 2 Functions Figure 2-50 Inverse time tripping curve for motor starting current Therefore, if the startup current I actually measured is smaller (or larger) than the nominal startup current ISTARTUP (parameter STARTUP CURRENT) entered at address 4102, the actual tripping time tTrip is lengthened (or shortened) accordingly (see Figure 2-50). Definite Time Overcurrent Tripping Characteristic (Locked Rotor Time) Tripping must be executed when the actual motor starting time exceeds the maximum allowable locked rotor time if the rotor is locked. The device can be informed about the locked rotor condition via the binary input (>Rotor locked"), e.g. from an external rpm-monitor. The motor startup condition is assumed when the current in any phase exceeds the current threshold I MOTOR START. At this instant, the timer LOCK ROTOR TIME is started. It should be noted that this timer starts every time the motor is started. This is therefore a normal operating condition that is neither indicated in the fault log nor causes the creation of a fault record. Only when the locked rotor time has elapsed, is the trip command issued. The locked rotor delay time (LOCK ROTOR TIME) is linked with the binary input >Rotor locked" over an AND gate. If the binary input is picked up after the set locked rotor time has expired, immediate tripping will take place regardless of whether the locked rotor condition occurred before, during or after the timeout. 155 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.8 Motor Protection (Motor Starting Protection 48, Motor Restart Inhibit 66) Logic Figure 2-51 Motor starting protection may be switched on or off. In addition, motor starting protection may be blocked via a binary input which will reset timers and pickup annunciations. The following figure illustrates the logic of motor starting protection. A pickup does not create messages in the trip log buffer. Fault recording is not started until a trip command has been issued. When the function drops out, all timers are reset. The annunciations disappear and a trip log is terminated should it have been created. Logic diagram of the Motor Starting Time Supervision SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 156 2 Functions 2.8.1.2 Setting Notes General Motor starting protection is only effective and accessible if address 141 48 = Enabled is set. If the function is not required Disabled is set. The function can be turned ON or OFF under address 4101 48. Startup Parameter The device is informed of the startup current values under normal conditions at address 4102 STARTUP CURRENT, the startup time at address 4103 STARTUP TIME. At all times this enables timely tripping if the value I2t calculated in the protection device is exceeded. If the startup time is longer than the permissible blocked rotor time, an external rpmcounter can initiate the definite-time tripping element via binary input (>Rotor locked"). A locked rotor leads to a loss of ventilation and therefore to a reduced thermal load capacity of the machine. For this reason the motor starting time monitor must issue a tripping command before reaching the thermal tripping characteristic valid for normal operation. A current above the threshold I MOTOR START (address 1107) is interpreted as a motor startup. Consequently, this value must be selected such that under all load and voltage conditions during motor startup the actual startup current safely exceeds the setting, but stays below the setting in case of permissible, momentary overload. Example: Motor with the following data: Rated Voltage VNom = 6600 V Nominal Current INom = 126 A Startup Current (primary) ISTARTUP = 624 A Long-Term Current Rating Imax = 135 A Startup Duration TSTARTUP = 8.5 s Current Transformers INom CTprim/INom CTsec = 200 A / 1A The setting for address STARTUP CURRENT (ISTARTUP) as a secondary value is calculated as follows: For reduced voltage, the startup current is also reduced almost linearly. At 80 % nominal voltage, the startup current in this example is reduced to 0.8 * ISTARTUP = 2.5. The setting for detection of a motor startup must lie above the maximum load current and below the minimum start-up current. If no other influencing factors are present (peak loads), the value for motor startup I MOTOR START set at address 1107 may be an average value: 157 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.8 Motor Protection (Motor Starting Protection 48, Motor Restart Inhibit 66) Based on the Long-Term Current Rating: For ratios deviating from nominal conditions, the motor tripping time changes: At 80% of nominal voltage (which corresponds to 80% of nominal starting current), the tripping time is: After the delay time 4104 LOCK ROTOR TIME has elapsed, the locked rotor binary input becomes effective and initiates a tripping signal. If the locked rotor time is set just long enough that during normal startup the binary input >Rotor locked" (FNo. 6805) is reliably reset during the delay time LOCK ROTOR TIME, faster tripping will be available during motor starting under locked rotor conditions. Note Overload protection characteristic curves are also effective during motor starting conditions. However, thermal profile during motor starting is constant. The setting at address I MOTOR START (1107) limits the operating range of the overload protection with regard to larger currents. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 158 2 Functions 2.8.2 Motor Restart Inhibit 66 The restart inhibit prevents restarting of the motor when this restart may cause the permissible thermal limits of the rotor to be exceeded. 2.8.2.1 Description General The rotor temperature of a motor generally remains well below its maximum admissible temperature during normal operation and also under increased load conditions. However, high startup currents required during motor startup increase the risk of the rotor being thermally damaged rather the stator, due to the short thermal constant of the rotor. To avoid that multiple starting attempts provoke tripping, a restart of the motor must be inhibited, if it is apparent that the thermal limit of the rotor will be exceeded during this startup attempt. Therefore, the 7SJ62/63/64 relays feature the motor start inhibit which outputs a blocking command until a new motor startup is permitted for the deactivated motor (restarting limit). The blocking signal must be configured to a binary output relay of the device whose contact is inserted in the motor starting circuit. Determining the Rotor Overtemperature Since the rotor current cannot be measured directly, the stator current must be used to generate a thermal profile of the rotor. The r.m.s. values of the currents are utilized for this. The rotor overtemperature R is calculated using the largest of these three currents. Therefore, it is assumed that the thermal limit values for the rotor winding are based on the manufacturer's data regarding the nominal starting current, maximum permissible starting time, and the number of starts permitted from cold (ncold) and warm (nwarm) conditions. From this data, the device performs the necessary calculations to establish the thermal profile of rotor and issues a blocking signal until the thermal profile of rotor decreases below the restarting limit at which point starting is permitted anew. 159 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.8 Motor Protection (Motor Starting Protection 48, Motor Restart Inhibit 66) Figure 2-52 Temperature curve at the rotor and the thermal profile during repeated start-up attempts Although the heat distribution on the rotor bars may severely differ during motor starting, the different maximum temperatures in the rotor are not pertinant for motor restart inhibit (see Figure 2-52). It is much more important to establish a thermal profile, after a complete motor start, that is appropriate for the protection of the motor's thermal condition. Figure 2-52 shows, as an example, the heating processes during repeated motor starts (three starts from cold operating condition), as well as the thermal profile in the protection relay. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 160 2 Functions Restarting Limit If the rotor temperature has exceeded the restart threshold, the motor cannot be restarted. The blocking signal is not lifted unless the rotor temperature has fallen below the restarting limit, that is, when exactly one start becomes possible without exceeding the excessive rotor temperature limit. Based on the specified motor parameters the device calculates the normalized restarting limit Restart: Where: Restart = Temperature threshold below which restarting is possible kR = k-factor for the rotor, calculated internally IStart = Startup current IB = Basic current Tm = Maximum starting time R = Thermal time constant of the rotor, calculated internally ncold = Permitted starts with cold motor The restarting limit Restart is displayed as operational measured value in the "thermal measured values". Restart Time The motor manufacturer allows a maximum allowable cold (ncold) and warm (nwarm) starting attempts. Afterwards the device must be allowed to cool off! A certain time must elapse - restarting time tRestart - to ensure that the rotor has cooled off. Equilibrium Time This thermal behavior is provided for in the protection as follows: Each time the motor is shutdown, the timer starts (address 4304 T Equal). It takes into account the different thermal conditions of the motor parts at the moment of shutdown. During the equilibrium time, the thermal profile of the rotor is not updated. It is maintained constant to replicate the equilization process in the rotor. Then the thermal model with the corresponding time constant (rotor time constant x extension factor) cools down. During the equilibrium time the motor cannot be restarted. As soon as the temperature sinks below the restarting threshold, the next restart attempt can be made. Minimum Inhibit Time Regardless of thermal profiles, some motor manufacturers require a minimum inhibit time after the maximum number of permissible starting attempts has been exceeded. The total duration of the inhibit signal depends on which of the times T Min Inhibit or TRestart is longer. Total Time TReclose 161 The total waiting time TReclose, before the motor can be restarted, therefore is composed of the equilibrium time and the time TRestart calculated from the thermal profile, and the value that is needed to drop below the limit for restarting. If the calculated temperature rise of the rotor is above the restarting limit when the motor is shut down, the minimum inhibit time will be started together with the equilibrium time. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.8 Motor Protection (Motor Starting Protection 48, Motor Restart Inhibit 66) Thus the total inhibit time TReclose can become equal to the minimum inhibit time if it is longer than the sum of the two first mentioned times: TReclose = TEqual + TRestart for TMin Inhibit < TEqual + TRestart TReclose = TMin Inhibit for TMin Inhibit TEqual + TRestart, if the calculated excessive temperature > restarting limit The operational measured value TReclose (visible in the thermal measured values) is the remaining time until the next restart is permissible. When the rotor excessive temperature is below the restarting limit and thus the next restarting attempt is permitted, the operational measured value for the waiting time has reached zero. Extension of Cool Down Time Constants In order to properly account for the reduced heat exchange when a self-ventilated motor is stopped, the cooling time constants can be increased relative to the time constants for a running machine with the factor K at STOP (address 4308). The criterion for the motor stop is the undershooting of a set current threshold BkrClosed I MIN. This understands that the motor idle current is greater than this threshold. The pickup threshold BkrClosed I MIN affects also the thermal overload protection function (see Section 2.10). While the motor is running, the heating of the thermal profile is modeled with the time constant R calculated from the motor ratings, and the cool down calculated with the time constant R x K at RUNNING (address 4309). In this way, the protection caters to the requirements in case of a slow cool down (slow temperature equilibrium). For calculation of the restarting time TRestart the following applies: with Behavior in Case of Power Supply Failure k at STOP - extension factor for the time constant = K at STOP, address 4308 k at RUNNING - extension factor for the time constant = K at RUNNING, address 4309 pre - thermal replica at the instant the motor is switched off (depends on operational condition) R - rotor time constant, calculated internally Depending on the setting in address 235 ATEX100 of Power System Data 1 (see Section 2.1.3.2) the value of the thermal replica is either reset to zero (ATEX100 = NO) if the power supply voltage fails, or cyclically buffered in a non-volatile memory (ATEX100 = YES) so that it is maintained in the event of auxiliary supply voltage failure. In the latter case, the thermal replica uses the stored value for calculation and matches it to the operating conditions. The first option is the default setting (see "Additional Information on the Protection of Explosion-Protected Motors of Protection Type Increased Safety "e", C53000-B1174-C157"/5/). For further details, see /5/. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 162 2 Functions Emergency Start If, for emergency reasons, motor starting that will exceed the maximum allowable rotor temperature must take place, the motor start blocking signal can be terminated via a binary input (>66 emer.start"), thus allowing a new starting attempt. The thermal rotor profile however continues to function and the maximum allowable rotor temperature will be exceeded. No motor shutdown will be initiated by motor start blocking, but the calculated excessive temperature of the rotor can be observed for risk assessment. Blocking If the motor restart inhibit function is blocked via binary input >BLOCK 66" or switched off, the thermal replica of the rotor overtemperature, the equilibrium time T Equal and the minimum inhibit time T MIN. INHIBIT are reset. Thus any blocking signal that is present or upcoming is disregarded. Via another binary input (>66 RM th.repl.") the thermal replica can be reset independently. This may be useful for testing and commissioning, and after a power supply voltage failure. 163 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.8 Motor Protection (Motor Starting Protection 48, Motor Restart Inhibit 66) Logic Figure 2-53 There is no pickup annunciation for the restart inhibit and no trip log is produced. The following figure shows the logic diagram for the restart inhibit. Logic diagram of the Restart Inhibit SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 164 2 Functions 2.8.2.2 Setting Notes General Restart inhibit is only effective and accessible if address 143 48 is set to Enabled. If not required, this function is set to Disabled. The function can be turned ON or OFF under address 4301 FCT 66.. Note When function settings of the restart inhibit are changed, the thermal profile of this function is reset. The restart inhibit acts on the starting process of a motor that is shut down. A motor is considered shut down if its current consumption falls below the settable threshold 212 BkrClosed I MIN. Therefore, this threshold must set lower than the motor idle current. Characteristic Values Many of the variables needed to calculate the rotor temperature are supplied by the motor manufacturer. Among these variables are the starting current ISTARTUP, the nominal motor current IMOT. NOM, the maximum allowable starting time T START MAX (address 4303), the number of allowable starts from cold conditions (ncold), and the number of allowable starts from warm conditions (nwarm). The starting current is entered at address 4302 IStart/IMOTnom , expressed as a multiple of nominal motor current. In contrast, the nominal motor current is entered as a secondary value, directly in amperes, at address 4305 I MOTOR NOMINAL. The number of warm starts allowed is entered at address 4306 (MAX.WARM STARTS) and the difference (#COLD-#WARM) between the number of allowable cold and warm starts is entered at address 4307. For motors without separate ventilation, the reduced cooling at motor stop can be accounted for by entering the factor K at STOP at address 4308. As soon as the current no longer exceeds the setting value entered at address 212 BkrClosed I MIN, motor standstill is detected and the time constant is increased by the extension factor configured. If no difference between the time constants is to be used (e.g. externally-ventilated motors), then the extension factor K at STOP should be set to 1. The cooling with the motor running is influenced by the extension factor 4309 K at RUNNING. This factor considers that motor running under load and a stopped motor do not cool down at the same speed. It becomes effective as soon as the current exceeds the value set at address 212 BkrClosed I MIN. With K at RUNNING = 1 the heating and the cooling time constant are the same at operating conditions (I > BkrClosed I MIN). Example: Motor with the following data: Nominal Voltage 165 VNom = 6600 V Nominal current INom = 126 A Startup current ISTARTUP = 624 A Startup Duration TSTARTUP = 8.5 s Allowable Starts with Cold Motor ncold = 3 Allowable Starts with Warm Motor nwarm = 2 Current Transformer 200 A / 1 A SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.8 Motor Protection (Motor Starting Protection 48, Motor Restart Inhibit 66) The following settings are derived from these data: The following settings are made: IStart/IMOTnom = 4.9 I MOTOR NOMINAL = 0.6 A T START MAX = 8.5 s MAX.WARM STARTS = 2 #COLD-#WARM = 1 For the rotor temperature equilibrium time (address 4304), a setting of. T Equal = 1 min has proven to be a good value. The value for the minimum inhibit time T MIN. INHIBIT depends on the requirements set by the motor manufacturer, or by the system conditions. It must in any case be higher than 4304 T Equal. In this example, a value was chosen that reflects the thermal profile (T MIN. INHIBIT = 6.0 min). The motor manufacturer's, or the requirements also determine also the extension factor for the time constant during cool-down, especially with the motor stopped. Where no other specifications are made, the following settings are recommended: K at STOP = 5 and K at RUNNING = 2. For a proper functioning, it is also important that the CT values and the current threshold for distinction between stopped and running motor (address 212 BkrClosed I MIN, recommended setting 0.1 IMOT.NOM) have been set correctly. An overview of parameters and their default settings is generally given in the setting tables. Temperature Behaviour during Changing Operating States For a better understanding of the above considerations several possible operating ranges in two different operating areas will be discussed in the following paragraph. Settings indicated above are to be used prevaling 3 cold and 2 warm startup attempts have resulted in the restart limit reaching 66.7%. A. Below the thermal restarting limit: 1. A normal startup brings the machine into a temperature range below the thermal restarting limit and the machine is stopped. The stop launches the equilibrium time 4304 T Equal and generates the message 66 TRIP". The equilibrium time expires and the message 66 TRIP" is cleared. During the time T Equal the thermal model remains "frozen" (see Figure 2-54, to the left). 2. A normal startup brings the machine into a temperature range below the thermal restarting limit, the machine is stopped and is started by an emergency startup without waiting for expiry of the equilibrium time. The equilibrium time is reset and the thermal profile is released and 66 TRIP" is reported to be cleared (see Figure 2-54, to the right). SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 166 2 Functions Figure 2-54 Startups according to examples A.1 and A.2 B. Above the thermal restarting limit: 1. A startup brings the machine from load operation into a temperature range far above the thermal restarting limit and the machine is stopped. The minimum inhibit time and the equilibrium time are started and 66 TRIP" is reported. The temperature cool-down below the restarting limit takes longer than 4310 T MIN. INHIBIT and 4304 T Equal, so that the time passing until the temperature falls below the temperature limit is the decisive factor for clearing the message 66 TRIP". The thermal profile remains "frozen" while the time expires (see Figure 255, to the left). 2. A startup brings the machine from load operation into a temperature range just above the thermal restarting limit and the machine is stopped. The minimum inhibit time and the equilibrium time are started and 66 TRIP" is reported. Although the temperature soon falls below the restarting limit, the blocking 66 TRIP" is preserved until the equilibrium time and the minimum inhibit time have expired (see Figure 2-55, to the right). 167 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.8 Motor Protection (Motor Starting Protection 48, Motor Restart Inhibit 66) Figure 2-55 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 Starting up according to examples B.1 and B.2 168 2 Functions 2.8.3 Motor (Motor Starting Protection 48, Motor Restart Inhibit 66) Functions Motor Starting Protection and Restart Inhibit for Motors associated with motor protection are described in the previous two sections and contain information concerning configuration. 2.8.3.1 Settings The table indicates region-specific default settings. Column C (configuration) indicates the corresponding secondary nominal current of the current transformer. Addr. Parameter 4101 FCT 48/66 4102 STARTUP CURRENT C Setting Options Default Setting Comments OFF ON OFF 48 / 66 Motor (Startup Monitor/Counter) 1A 0.50 .. 16.00 A 5.00 A Startup Current 5A 2.50 .. 80.00 A 25.00 A 4103 STARTUP TIME 1.0 .. 180.0 sec 10.0 sec Startup Time 4104 LOCK ROTOR TIME 0.5 .. 120.0 sec; 2.0 sec Permissible Locked Rotor Time 4301 FCT 66 OFF ON OFF 66 Startup Counter for Motors 4302 IStart/IMOTnom 1.10 .. 10.00 4.90 I Start / I Motor nominal 4303 T START MAX 3 .. 320 sec 10 sec Maximum Permissible Starting Time 4304 T Equal 0.0 .. 320.0 min 1.0 min Temperature Equalizaton Time 4305 I MOTOR NOMINAL 1A 0.20 .. 1.20 A 1.00 A Rated Motor Current 5A 1.00 .. 6.00 A 5.00 A 4306 MAX.WARM STARTS 1 .. 4 2 Maximum Number of Warm Starts 4307 #COLD-#WARM 1 .. 2 1 Number of Cold Starts Warm Starts 4308 K at STOP 0.2 .. 100.0 5.0 Extension of Time Constant at Stop 4309 K at RUNNING 0.2 .. 100.0 2.0 Extension of Time Constant at Running 4310 T MIN. INHIBIT 0.2 .. 120.0 min 6.0 min Minimum Restart Inhibit Time 169 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.8 Motor Protection (Motor Starting Protection 48, Motor Restart Inhibit 66) 2.8.3.2 Information List No. Information Type of Information Comments 4822 >BLOCK 66 SP >BLOCK Motor Startup counter 4823 >66 emer.start SP >Emergency start 4824 66 OFF OUT 66 Motor start protection OFF 4825 66 BLOCKED OUT 66 Motor start protection BLOCKED 4826 66 ACTIVE OUT 66 Motor start protection ACTIVE 4827 66 TRIP OUT 66 Motor start protection TRIP 4828 >66 RM th.repl. SP >66 Reset thermal memory 4829 66 RM th.repl. OUT 66 Reset thermal memory 6801 >BLK START-SUP SP >BLOCK Startup Supervision 6805 >Rotor locked SP >Rotor locked 6811 START-SUP OFF OUT Startup supervision OFF 6812 START-SUP BLK OUT Startup supervision is BLOCKED 6813 START-SUP ACT OUT Startup supervision is ACTIVE 6821 START-SUP TRIP OUT Startup supervision TRIP 6822 Rotor locked OUT Rotor locked 6823 START-SUP pu OUT Startup supervision Pickup SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 170 2 Functions 2.9 Frequency Protection 81 O/U The frequency protection function detects abnormally high and low frequencies in the system or in electrical machines. If the frequency lies outside the allowable range, appropriate actions are initiated, such as load shedding or separating a generator from the system. Applications * A decrease in system frequency occurs when the system experiences an increase in the real power demand, or when a malfunction occurs with a generator governor or automatic generation control (AGC) system. The frequency protection function is also used for generators, which (for a certain time) operate to an island network. This is due to the fact that the reverse power protection cannot operate in case of a drive power failure. The generator can be disconnected from the power system using the frequency decrease protection. * An increase in system frequency occurs, e.g. when large blocks of load (island network) are removed from the system, or again when a malfunction occurs with a generator governor. This entails risk of self-excitation for generators feeding long lines under no-load conditions. 2.9.1 Description Detection of Frequency The frequency is detected from the phase-to-phase voltage VA-B applied to the device. If the amplitude of this voltage is too small, one of the other phase-to-phase voltages is used instead. With the applications of filters and repeated measurements, the frequency evaluation is free from harmonic influences and very accurate. Underfrequency and Overfrequency Protection Frequency protection consists of four frequency elements. To make protection flexible for different power system conditions, theses stages can be used alternatively for frequency decrease or increase separately, and can be independently set to perform different control functions. The parameter setting decides for what purpose the particular element will be used: * Set the pickup threshold lower than nominal frequency if the element is to be used for underfrequency protection. * Set the pickup threshold lower than nominal frequency if the element is to be used for overfrequency protection. * If the threshold is set equal to the nominal frequency, the element is inactive. Operating Ranges 171 The frequency can be determined if for three-phase voltage transformer connections the positive frequency component of the voltages or for single-phase voltage transformer connections the corresponding voltage is present and of sufficient magnitude. If the measured voltage drops below a settable value Vmin, the frequency protection is blocked since a precise frequency value can no longer be calculated from the signal under these conditions. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.9 Frequency Protection 81 O/U Time Delays / Logic Each frequency element has an associated settable time delay. When the time delay elapses, a trip signal is generated. When a frequency element drops out, the tripping command is immediately terminated, but not before the minimum command duration has elapsed. Each of the four frequency elements can be blocked individually by binary inputs. The following figure shows the logic diagram for the frequency protection function. Figure 2-56 2.9.2 Logic diagram of the frequency protection Setting Notes General Frequency protection is only in effect and accessible if address 154 81 O/U is set to Enabled during configuration of protective functions. If the fuction is not required Disabled is set. The function can be turned ON or OFF under address 5401 FCT 81 O/U. Minimum Voltage Address 5402 Vmin is used to set the minimum voltage. Frequency protection is blocked as soon as the minimum voltage is undershot. On all three-phase connections and single-phase connections of a phase-to-phase voltage, the threshold must be set as a phase-to-phase value. With a single-phase phase-to-ground connection the threshold is set as a phase-to-ground voltage. Pickup Values The nominal system frequency is programmed in Power System Data 1, and the pickup settings for each of the frequency elements 81-1 PICKUP to 81-4 PICKUP determines whether the function will be used for overfrequency or underfrequency protection. Set the pickup threshold lower than nominal frequency if the element is to SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 172 2 Functions be used for underfrequency protection. Set the pickup threshold higher than nominal frequency if the element is to be used for overfrequency protection. Note If the threshold is set equal to the nominal frequency, the element is inactive. If underfrequency protection is used for load shedding purposes, then the frequency settings relative to other feeder relays are generally based on the priority of the customers served by the protective relay. Normally a graded load shedding is required that takes into account the importance of the consumers or consumer groups. Further application examples exist in the field of power stations. The frequency values to be set mainly depend, also in these cases, on the specifications of the power system / power station operator. In this context, the frequency decrease protection safeguards the power station's own demand by disconnecting it from the power system on time. The turbo governor regulates the machine set to the nominal speed. Consequently, the station's own demands can be continuously supplied at nominal frequency. Under the assumption that the apparent power is reduced by the same degree, turbine-driven generators can, as a rule, be continuously operated down to 95% of the nominal frequency. However, for inductive consumers, the frequency reduction not only means an increased current input, but also endangers stable operation. For this reason, only a short-term frequency reduction down to about 48 Hz (for fN = 50 Hz) or 58 Hz (for fN = 60 Hz) is permissible. A frequency increase can, for example, occur due to a load shedding or malfunction of the speed regulation (e.g. in an island network). In this way, the frequency increase protection can, for example, be used as overspeed protection. Time Delays 173 The time delays (definite time) 81-1 DELAY to 81-4 DELAY entered at addresses 5405, 5408, 5411 and 5414 allow the device to prioritize or sort corrective actions based on the degree to which the actual system frequency departs (upward or downward) from the nominal system frequency, e.g. for load shedding equipment. The set times are additional time delays not including the operating times (measuring time, drop-out time) of the protective function. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.9 Frequency Protection 81 O/U 2.9.3 Settings Addr. Parameter Setting Options Default Setting Comments 5401 FCT 81 O/U OFF ON OFF 81 Over/Under Frequency Protection 5402 Vmin 10 .. 150 V 65 V Minimum required voltage for operation 5403 81-1 PICKUP 45.50 .. 54.50 Hz 49.50 Hz 81-1 Pickup 5404 81-1 PICKUP 55.50 .. 64.50 Hz 59.50 Hz 81-1 Pickup 5405 81-1 DELAY 0.00 .. 100.00 sec; 60.00 sec 81-1 Time Delay 5406 81-2 PICKUP 45.50 .. 54.50 Hz 49.00 Hz 81-2 Pickup 5407 81-2 PICKUP 55.50 .. 64.50 Hz 59.00 Hz 81-2 Pickup 5408 81-2 DELAY 0.00 .. 100.00 sec; 30.00 sec 81-2 Time Delay 5409 81-3 PICKUP 45.50 .. 54.50 Hz 47.50 Hz 81-3 Pickup 5410 81-3 PICKUP 55.50 .. 64.50 Hz 57.50 Hz 81-3 Pickup 5411 81-3 DELAY 0.00 .. 100.00 sec; 3.00 sec 81-3 Time delay 5412 81-4 PICKUP 45.50 .. 54.50 Hz 51.00 Hz 81-4 Pickup 5413 81-4 PICKUP 55.50 .. 64.50 Hz 61.00 Hz 81-4 Pickup 5414 81-4 DELAY 0.00 .. 100.00 sec; 30.00 sec 81-4 Time delay 2.9.4 Information List No. Information Type of Information Comments 5203 >BLOCK 81O/U SP >BLOCK 81O/U 5206 >BLOCK 81-1 SP >BLOCK 81-1 5207 >BLOCK 81-2 SP >BLOCK 81-2 5208 >BLOCK 81-3 SP >BLOCK 81-3 5209 >BLOCK 81-4 SP >BLOCK 81-4 5211 81 OFF OUT 81 OFF 5212 81 BLOCKED OUT 81 BLOCKED 5213 81 ACTIVE OUT 81 ACTIVE 5214 81 Under V Blk OUT 81 Under Voltage Block 5232 81-1 picked up OUT 81-1 picked up 5233 81-2 picked up OUT 81-2 picked up 5234 81-3 picked up OUT 81-3 picked up 5235 81-4 picked up OUT 81-4 picked up 5236 81-1 TRIP OUT 81-1 TRIP 5237 81-2 TRIP OUT 81-2 TRIP 5238 81-3 TRIP OUT 81-3 TRIP 5239 81-4 TRIP OUT 81-4 TRIP SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 174 2 Functions 2.10 Thermal Overload Protection 49 The thermal overload protection is designed to prevent thermal overloads from damaging the protected equipment. The protection function models a thermal profile of the object being protected (overload protection with memory capability). Both the history of an overload and the heat loss to the environment are taken into account. Applications * In particular, the thermal overload protection allows the thermal status of motors, generators and transformers to be monitored. * If an additional thermal input is available, the thermal profile may take the actual ambient or coolant temperature into consideration. 2.10.1 Description Thermal Profile The device calculates the overtemperatures in accordance with a single-body thermal model, based on the following differential equation: with Present overtemperature related to the final overtemperature at maximum allowed phase current k * INom Obj th Thermal time constant of the protected object's heating I Present rms value of phase current k k-factor indicating the maximum permissible constant phase current referred to the nominal current of the protected object INom Obj. Nominal current of protected object with u Measured ambient temperature or coolant temperature Nom Temperature at object nominal current If the ambient or coolant temperature is not measured, a constant value of u = 40 C or 104F is assumed so that u'= 0. The protection feature models a thermal profile of the equipment being protected (overload protection with memory capability). Both the history of an overload and the heat loss to the environment are taken into account. When the calculated overtemperature reaches the first settable threshold 49 ALARM, an alarm annunciation is issued, e.g. to allow time for the load reduction measures to take place. When the calculated overtemperature reaches the second thresh- 175 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.10 Thermal Overload Protection 49 old, the protected equipment may be disconnected from the system. The highest overtemperature calculated from the three phase currents is used as the criterion. The maximum thermally-permissible continuous current Imax is described as a multiple of the object nominal current INom Obj.: Imax = k * INom Obj. In addition to the k factor (parameter 49 K-FACTOR), the TIME CONSTANT th and the alarm temperature 49 ALARM (in percent of the trip temperature TRIP) must be specified. Overload protection also features a current warning element (I ALARM) in addition to the temperature warning stage. The current warning element may report an overload current prematurely, even if the calculated operating temperature has not yet attained the warning or tripping levels. Coolant Temperature (Ambient Temperature) The device can account for external temperatures. Depending on the type of application, this may be a coolant or ambient temperature. The temperature can be measured via a temperature detection unit (RTD-box). For this purpose, the required temperature detector is connected to detector input 1 of the first RTD-box (corresponds to RTD 1). If incorrect temperature values are measured or there are disturbances between the RTD-box and the device, an alarm will be issued and the standard temperature of u = 104 F or 40 C is used for calculation with the ambient temperature detection simply being ignored. When detecting the coolant temperature, the maximum permissible current Imax is influenced by the temperature difference of the coolant (in comparison with the standard value = 104 F or 40 C). If the ambient or coolant temperature is low, the protected object can support a higher current than it does when the temperature is high. Current Limiting In order to ensure that overload protection, on occurrence of high fault currents (and with small time constants), does not result in extremely short trip times thereby perhaps affecting time grading of the short circuit protection, the thermal model is frozen (kept constant) as soon as the current exceeds the threshold value 1107 I MOTOR START. Extension of Time Constants When using the device to protect motors, the varying thermal response at standstill or during rotation may be correctly evaluated. When running down or at standstill, a motor without external cooling looses heat more slowly, and a longer thermal time constant must be used for calculation. For a motor that is switched off, the 7SJ62/63/64 increases the time constant th by a programmable factor (k factor). The motor is considered to be off when the motor currents drop below a programmable minimum current setting BkrClosed I MIN (refer to "Current Flow Monitoring" in Section 2.1.3). For externally-cooled motors, cables and transformers, the K-FACTOR = 1. Blocking The thermal memory may be reset via a binary input (>RES 49 Image"). The current-related overtemperature value is reset to zero. The same is accomplished via the binary input (>BLOCK 49 O/L"); in this case the entire overload protection is blocked completely, including the current warning stage. When motors must be started for emergency reasons, temperatures above the maximum permissible overtemperature can be allowed by blocking the tripping signal via a binary input (>EmergencyStart"). Since the thermal profile may have exceeded the tripping temperature after initiation and drop out of the binary input has taken place, the protection function features a programmable run-on time interval (T SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 176 2 Functions EMERGENCY) which is started when the binary input drops out and continues suppressing a trip signal. Tripping by the overload protection will be defeated until this time interval elapses. The binary input affects only the tripping signal. There is no effect on the trip log nor does the thermal profile reset. Behaviour in Case of Power Supply Failure 177 Depending on the setting in address 235 ATEX100 of Power System Data 1 (see Section 2.1.3) the value of the thermal replica is either reset to zero (ATEX100 = NO) if the power supply voltage fails, or cyclically buffered in a non-volatile memory (ATEX100 = YES) so that it is maintained in the event of auxiliary supply voltage failure. In the latter case, the thermal replica uses the stored value for calculation and matches it to the operating conditions. The first option is the default setting (see /5/). For further details, see /5/. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.10 Thermal Overload Protection 49 The following figure shows the logic diagram for the overload protection function. Figure 2-57 Logic diagram of the overload protection SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 178 2 Functions 2.10.2 Setting Notes General The overload protection is only in effect and accessible if address 142 49 = No ambient temp or = With amb. temp. during configuration. If the function is not required Disabled is set. Transformers and cable are prone to damage by overloads that last for an extended period of time. Overloads cannot and should not be detected by fault protection. Time overcurrent protection should be set high enough to only detect faults since these must be cleared in a short time. Short time delays, however, do neither allow measures to discharge overloaded equipment nor do they permit to take advantage of its (limited) overload capacity. The protective relays 7SJ62/63/64 feature a thermal overload protective function with a thermal tripping curve which may be adapted to the overload tolerance of the equipment being protected (overload protection with memory capability). Overload protection may be switched ON or OFF or Alarm Only at address 4201 FCT 49. If overload protection is ON, tripping, trip log and fault recording is possible. When setting Alarm Only no trip command is given, no trip log is initiated and no spontaneous fault annunciation is shown on the display. Note Changing the function parameters resets the thermal replica. The thermal model is frozen (kept constant) as soon as the current exceeds the threshold value 1107 I MOTOR START. Overload Parameter k-factor The overload protection is set with quantities per unit. The nominal current INom Obj. of the protected object (motor, transformer, cable) is used as a basis for overload detection. The thermally permissible continuous current Imax prim allows to calculate a factor kprim: The thermally-permissible continuous current for the equipment being protected is known from the manufacturers specifications. This function is normally not applicable to overhead lines since the current capability of overhead lines is generally not specified. For cables, the permissible continuous current is dependent on the cross-section, insulating material, design, and the cable routing, among other things. It may be taken from pertinent tables, or is specified by the cable manufacturer. If no specifications are available, a value of 1.1 times the nominal current rating may be assumed. The 49 K-FACTOR to be set in the device (address 4202) refers to the secondary nominal current of the protective relay. The following data apply for the conversion: 179 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.10 Thermal Overload Protection 49 with Imax prim Permissible thermal primary current of the motor INom Obj. Nominal current of the protected object INom CT prim Nominal primary CT current Example: Motor and transformer with the following data: Permissible Continuous Current Time Constant Imax prim = 1.2 * INom Obj. Nominal Motor Current INom Obj. = 1100 A Current Transformer 1200 A / 1 A The overload protection tracks overtemperature progression, employing a thermal differential equation whose steady state solution is an exponential function. The TIME CONSTANT th (set at address 4203) is used in the calculation to determine the threshold of overtemperature and thus, the tripping temperature. For cable protection, the heat-gain time constant is determined by cable specifications and by the cable environment. If no time-constant specification is available, it may be determined from the short-term load capability of the cable. The 1-sec current, i.e. the maximum current permissible for a one-second period of time, is often known or available from tables. Then, the time constant may be calculated with the formula: If the short-term load capability is given for an interval other than one sec, the corresponding short-term current is used in the above formula instead of the 1-sec current, and the result is multiplied by the given duration. For example, if the 0.5-second current rating is known: It is important to note, however, that the longer the effective duration, the less accurate the result. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 180 2 Functions Example: Cable and current transformer with the following data: Permissible Continuous Current Imax = 500 A at u = 104 F or 40 C Maximum current for 1 s I1s = 45 * Imax = 22.5 kA Current Transformer 600 A / 1 A Example: Cable and current transformer with the following data: Thus results: The settings are: 49 K-FACTOR = 0.83; TIME CONSTANT = 33.7 min Warning Temperature Level By setting the thermal warning level 49 ALARM at address 4204, a warning message can be issued prior to tripping, thus allowing time for load curtailment procedures to be implemented. This warning level simultaneously represents the dropout level for the tripping signal. Only when this threshold is undershot, the tripping command is reset and the protected equipment may be returned to service. The thermal warning level is given in % of the tripping temperature level. A current warning level is also available (address 4205 I ALARM). The setting corresponds to secondary amperes, and should be set equal to, or slightly less than, permissible continuous current (k * INom sec). It may be used in lieu of the thermal warning level by setting the thermal warning level to 100 % and thereby practically disabling it. Extension of Time Constants TIME CONSTANT set in address 4203 is valid for a running motor. When a motor without external cooling is running down or at standstill, the motor cools down more slowly. This behavior can be modeled by increasing the time constant by factor KFACTOR, set at address 4207. Motor stop is detected if the current falls below the threshold value BkrClosed I MIN of the current flow monitoring (see margin heading "Current Flow Monitoring" in Section 2.1.3.2). This assumes that the motor idle current is greater than this threshold. The pickup threshold BkrClosed I MIN affects also the following protection functions: breaker failure protection and restart inhibit for motors. If no differentiation of the time constants is necessary (e.g. externally-cooled motors, cables, lines, etc.) the K-FACTOR is set at 1 (default setting value). Dropout Time after Emergency Starting 181 The dropout time to be entered at address 4208 T EMERGENCY must ensure that after an emergency startup and after dropout of the binary input >EmergencyStart" the trip command is blocked until the thermal replica is below the dropout threshold again. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.10 Thermal Overload Protection 49 Ambient or Coolant Temperature The indications specified up to now are sufficient for a temperature rise replica. The ambient or coolant temperature, however, can also be processed. This has to be communicated to the device as digitalized measured value via the interface. During configuration the parameter 142 49 must be set to With amb. temp.. If the ambient temperature detection is used, the user must be aware that the 49 KFACTOR to be set refers to an ambient temperature of 104 F or 40 C, i.e. it corresponds to the maximum permissible current at a temperature of 104 F or 40 C. All calculations are performed with standardized quantities. The ambient temperature must also be standardized. The temperature with nominal current is used as standardized quantity. If the nominal current deviates from the nominal CT current, the temperature must be adapted according to the following formula. In address 4209 or 4210 49 TEMP. RISE I the temperature adapted to the nominal transformer current is set. This setting value is used as standardization quantity of the ambient temperature input. with Nom sec Machine temperature with secondary nominal current = setting at the protective relay (address 4209 or 4210) Nom mach Machine temperature with nominal machine current INom CT prim Nominal Primary CT Current INom mach Nominal Current of the Machine If the temperature input is used, the trip times change if the coolant temperature deviates from the internal reference temperature of 104 F or 40 C. The following formula can be used to calculate the trip time: with th TIME CONSTANT (address 4203) k 49 K-FACTOR (address 4202) INom Nominal device current in A I Fault current through phase in A IPre Previous load current Ut=0 Coolant temperature input in C with t=0 Nom Temperature with Nominal Current INom(Address 4209 49 TEMP. RISE I) u Coolant temperature input (scaling with address 4209 or 4210) SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 182 2 Functions Example: Machine: INom Mach = 483 A Imax Mach=1.15 INom at K = 104 F or 40 C Nom Mach = 199.4 F or 93 C Temperature at INom Mach th = 600 s (thermal time constant of the machine) Current transformer: 500 A / 1 A Motor Starting Recognition 183 The motor starting is detected when setting I MOTOR START at address 1107 is exceeded. Information on how to perform the configuration is given under "Recognition of Running Condition (only for motors)" in Subsection2.1.3.2. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.10 Thermal Overload Protection 49 2.10.3 Settings Addresses which have an appended "A" can only be changed with DIGSI, under "Display Additional Settings". The table indicates region-specific default settings. Column C (configuration) indicates the corresponding secondary nominal current of the current transformer. Addr. Parameter C Setting Options Default Setting Comments 4201 FCT 49 OFF ON Alarm Only OFF 49 Thermal overload protection 4202 49 K-FACTOR 0.10 .. 4.00 1.10 49 K-Factor 4203 TIME CONSTANT 1.0 .. 999.9 min 100.0 min Time Constant 4204 49 ALARM 50 .. 100 % 90 % 49 Thermal Alarm Stage 4205 I ALARM 1A 0.10 .. 4.00 A 1.00 A 5A 0.50 .. 20.00 A 5.00 A Current Overload Alarm Setpoint 4207A K-FACTOR 1.0 .. 10.0 1.0 Kt-FACTOR when motor stops 4208A T EMERGENCY 10 .. 15000 sec 100 sec Emergency time 4209 49 TEMP. RISE I 40 .. 200 C 100 C 49 Temperature rise at rated sec. curr. 4210 49 TEMP. RISE I 104 .. 392 F 212 F 49 Temperature rise at rated sec. curr. 2.10.4 Information List No. Information Type of Information Comments 1503 >BLOCK 49 O/L SP >BLOCK 49 Overload Protection 1507 >EmergencyStart SP >Emergency start of motors 1511 49 O / L OFF OUT 49 Overload Protection is OFF 1512 49 O/L BLOCK OUT 49 Overload Protection is BLOCKED 1513 49 O/L ACTIVE OUT 49 Overload Protection is ACTIVE 1515 49 O/L I Alarm OUT 49 Overload Current Alarm (I alarm) 1516 49 O/L Alarm OUT 49 Overload Alarm! Near Thermal Trip 1517 49 Winding O/L OUT 49 Winding Overload 1521 49 Th O/L TRIP OUT 49 Thermal Overload TRIP 1580 >RES 49 Image SP >49 Reset of Thermal Overload Image 1581 49 Image res. OUT 49 Thermal Overload Image reset SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 184 2 Functions 2.11 Monitoring Functions The device is equipped with extensive monitoring capabilities - both for hardware and software. In addition, the measured values are also constantly monitored for plausibility, therefore, the current transformer and voltage transformer circuits are largely integrated into the monitoring. 2.11.1 Measurement Supervision 2.11.1.1 General The device monitoring extends from the measuring inputs to the binary outputs. Monitoring checks the hardware for malfunctions and impermissible conditions. Hardware and software monitoring described in the following are enabled continuously. Settings (including the possibility to activate and deactivate the monitoring function) refer to monitoring of external transformers circuits. 2.11.1.2 Hardware Monitoring Auxiliary and Reference Voltages The processor voltage of 5 VDC is monitored by the hardware since if it goes below the minimum value, the processor is no longer functional. The device is under such a circumstance removed from operation. When the supply voltage returns, the processor system is restarted. Failure of or switching off the supply voltage removes the device from operation and a message is immediately generated by a normally closed contact. Brief auxiliary voltage interruptions of less than 50 ms do not disturb the readiness of the device (for nominal auxiliary voltage > 110 VDC). The processor monitors the offset and reference voltage of the ADC (analog-digital converter). The protection is suspended if the voltages deviate outside an allowable range, and lengthy deviations are reported. Buffer Battery The buffer battery, which ensures operation of the internal clock and storage of counters and messages if the auxiliary voltage fails, is periodically checked for charge status. If it is less than an allowed minimum voltage, then the Fail Battery" message is issued. Memory Components All working memories (RAMs) are checked during start-up. If a fault occurs, the start is aborted and an LED starts flashing. During operation the memories are checked with the help of their checksum. For the program memory, the cross sum is formed cyclically and compared to the stored program cross sum. For the settings memory, the cross sum is formed cyclically and compared to the cross sum that is freshly generated each time a setting process takes place. If a fault occurs the processor system is restarted. 185 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.11 Monitoring Functions Scanning Scanning and the synchronization between the internal buffer components are constantly monitored. If any deviations cannot be removed by renewed synchronization, then the processor system is restarted. 2.11.1.3 Software Monitoring Watchdog For continuous monitoring of the program sequences, a time monitor is provided in the hardware (hardware watchdog) that expires upon failure of the processor or an internal program, and causes a complete restart of the processor system. An additional software watchdog ensures that malfunctions during the processing of programs are discovered. This also initiates a restart of the processor system. If such a malfunction is not cleared by the restart, an additional restart attempt is begun. After three unsuccessful restarts within a 30 second window of time, the device automatically removes itself from service and the red Error" LED lights up. The readiness relay drops out and indicates device malfunction" with its normally closed contact. Offset Monitoring This monitoring function checks all ring buffer data channels for corrupt offset replication of the analog/digital transformers and the analog input paths using offset filters. The eventual offset errors are detected using DC voltage filters and the associated samples are corrected up to a specific limit. If this limit is exceeded an indication is issued (191 Error Offset") that is part of the warn group annunciation (annunciation 160). As increased offset values affect the reliability of measurements taken, we recommend to send the device to the OEM plant for corrective action if this annunciation continuously occurs. 2.11.1.4 Monitoring of the Transformer Circuits Interruptions or short circuits in the secondary circuits of the current and voltage transformers, as well as faults in the connections (important for commissioning!), are detected and reported by the device. The measured quantities are cyclically checked in the background for this purpose, as long as no system fault is present. Measurement Value Acquisition - Currents Up to four input currents are measured by the device. If the three phase currents and the ground fault current from the current transformer star point or a separated ground current transformer of the line to be protected are connected to the device, their digitised sum must be zero. Faults in the current circuit are recognised if IF = | iA + iB + iC + kI * iN | > I THRESHOLD * INom + I FACTOR * Imax The factor kI takes into account a possible difference in the neutral current transformer ratio IN (e.g. toroidal current transformer see addresses 217, 218, 204 and 205): I THRESHOLD and I FACTOR are programmable settings. The component I FACTOR * Imax takes into account the permissible current proportional ratio errors of the input transformer which are particularly prevalent during large short-circuit currents (Figure 2-58). The dropout ratio is about 97 %. This malfunction is reported as Failure I". SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 186 2 Functions Figure 2-58 CurrentSymmetry Current sum monitoring During normal system operation, symmetry among the input currents is expected. The symmetry is monitored in the device by magnitude comparison. The smallest phase current is compared to the largest phase current. Asymmetry is detected if | Imin | / | Imax | < BAL. FACTOR I as long as Imax / INom > BALANCE I LIMIT / INom is valid. Thereby Imax is the largest of the three phase currents and Imin the smallest. The symmetry factor BAL. FACTOR I represents the allowable asymmetry of the phase currents while the limit value BALANCE I LIMIT is the lower limit of the operating range of this monitoring (see Figure 2-59). Both parameters can be set. The dropout ratio is about 97%. This malfunction is reported as Fail I balance". Figure 2-59 187 Current symmetry monitoring SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.11 Monitoring Functions VoltageSymmetry During normal system operation (i.e. the absence of a short-circuit fault), symmetry among the input voltages is expected. Because the phase-to-phase voltages are insensitive to ground connections, the phase-to-phase voltages are used for the symmetry monitoring. If the device is connected to the phase-to-ground voltages, then the phase-to-phase voltages are calculated accordingly, whereas if the device is connected to phase-to-phase voltages and the displacement voltage, then the third phase-tophase voltage is calculated accordingly. Whereas if the device is connected to phaseto-phase voltages and the displacement voltage V0, then the third phase-to-phase voltage is calculated accordingly. From the phase-to-phase voltages, the protection generates the rectified average values and checks the symmetry of their absolute values. The smallest phase voltage is compared with the largest phase voltage. Asymmetry is recognized if: | Vmin | / | Vmax | < BAL. FACTOR V as long as | Vmax | > BALANCE V-LIMIT. Where Vmax is the highest of the three voltages and Vmin the smallest. The symmetry factor BAL. FACTOR V is the measure for the asymmetry of the conductor voltages; the limit value BALANCE V-LIMIT is the lower limit of the operating range of this monitoring (see Figure 2-60). Both parameters can be set. The dropout ratio is about 97%. This malfunction is reported as Fail V balance". Figure 2-60 Current and Voltage Phase Sequence Voltage symmetry monitoring To detect swapped phase connections in the voltage and current input circuits, the phase sequence of the phase-to-phase measured voltages and the phase currents are checked by monitoring the sequence of same polarity zero transitions of the voltages. Direction measurement with normal voltages, path selection for fault location, and negative sequence detection all assume a phase sequence of "abc". Phase rotation of measurement quantities is checked by verifying the phase sequences. Voltages: VA before VB before VC and Currents: IA before IB before IC. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 188 2 Functions Verification of the voltage phase rotation is done when each measured voltage is at least | VA|, |VB|, |VC| > 40 V/3. Verification of the current phase rotation is done when each measured current is at least: |IA|, |IB|, |IC| > 0.5 IN. For abnormal phase sequences, the messages Fail Ph. Seq. V" or Fail Ph. Seq. I" are issued, along with the switching of this message Fail Ph. Seq.". For applications in which an opposite phase sequence is expected, the protective relay should be adjusted via a binary input or a programmable setting. If the phase sequence is changed in the device, phases B and C internal to the relay are reversed, and the positive and negative sequence currents are thereby exchanged (see also Section 2.21.2). The phase-related messages, malfunction values, and measured values are not affected by this. 2.11.1.5 Measurement Voltage Failure Detection Requirements The function measurement voltage failure detection, in given briefly Fuse Failure Monitor" (FFM), only operates under the following condition. * Three phase-to-ground voltages are connected; with phase-phase voltages and VN or single-phase connection, the function is disabled, as monitoring cannot occur. Purpose of the Fuse Failure Monitor In case of a measuring voltage failure caused by a fault or a broken wire in the voltage transformer secondary system, zero voltage may be "seen" by individual measuring loops. The displacement voltage element of the sensitive ground fault detection, the undervoltage protection and the synchronization function in the 7SJ64 can thereby acquire incorrect measuring results. In grounded systems, the function Fuse Failure Monitor" (FFM) can take effect, unless three phase-to-ground voltages are connected to the device. Of course, supervision of the miniature circuit breaker and the Fuse Failure Monitor can be used at the same time. Functionality Depending on the settings and the MLFB, the FFM operates with the measured or the calculated values VN or IN. If zero sequence voltage occurs without a ground fault current being registered simultaneously, then there is an asymmetrical fault in the secondary circuit of the voltage transformer. The displacement voltage element of the sensitive ground fault detection, the directional time overcurrent protection (phase and ground function), the undervoltage protection and the synchronization function in the 7SJ64 are blocked. The latter, however is not blocked if Direct CO is selected and therefore no measurement is required. Note On systems where the ground fault current is very small or absent (e.g. ungrounded supply transformers), fuse failure monitoring must not be used! 189 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.11 Monitoring Functions The FFM will pick up on a ground voltage VN which is bigger than the threshold specified under 5302 FUSE FAIL 3Vo and on a ground current IN which is smaller than the threshold specified under 5303 FUSE FAIL RESID. Pickup will take place on the specified values. A hysteresis is integrated for dropout, of 105% where IN or of 95% where VN. In case of a low-current asymmetrical fault in the power system with weak infeed, the ground current caused by the fault might lie below the pickup threshold of the Fuse Failure Monitor. Overfunctioning of the Fuse Failure Monitor can, however, cause the feeder protection equipment to fail since it will block all protective functions that use voltage signals. Such an overfunction of the FFM is avoided by additionally checking the phase currents. If at least one phase currents lies above the pickup threshold of 5303 FUSE FAIL RESID, it can be assumed that the zero current created by a short-circuit would equally exceed this limit. The following conditions hold to immediately detect a fault existing after activation of the FFM: If a ground current IN occurs within 10 seconds after the Fuse-Failure criterion was detected, a fault is assumed and the blocking by the Fuse Failure Monitor is blocked for as long as the fault persists. If the voltage failure criterion applies for longer than approx. 10 seconds, the blocking takes permanent effect. After the time has elapsed it can be assumed that a Fuse Failure has actually occurred. The blocking is lifted automatically 10 seconds after the voltage criterion has disappeared as a result of the secondary circuit fault being cleared, and the entire protection function is released. The following figure shows the logic diagram of the Fuse Failure Monitor. Figure 2-61 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 Logic diagram of the Fuse Failure Monitor 190 2 Functions 2.11.1.6 Setting Notes General Measured value monitoring can be turned ON or OFF at address 8101 MEASURE. SUPERV. The fuse-failure monitor can be set ON or OFF at address 5301 FUSE FAIL MON.. Note On systems where the ground fault current is very small or absent (e.g. ungrounded supply transformers), fuse failure monitoring must not be used! Measured Value Monitoring The sensitivity of the measured value monitor can be modified. Default values which are sufficient in most cases are preset. If especially high operating asymmetry in the currents and/or voltages are to be expected during operation, or if it becomes apparent during operation that certain monitoring functions activate sporadically, then the setting should be less sensitive. Address 8102 BALANCE V-LIMIT determines the limit voltage (phase-to-phase), above which the voltage symmetry monitor is effective. Address 8103 BAL. FACTOR V is the associated symmetry factor; that is, the slope of the symmetry characteristic curve. Address 8104 BALANCE I LIMIT determines the limit current, above which the current symmetry monitor is effective. Address 8105 BAL. FACTOR I is the associated symmetry factor; that is, the slope of the symmetry characteristic curve. Address 8106 I THRESHOLD determines the limit current, above which the current sum monitor is activated (absolute portion, only relative to IN). The relative portion (relative to the maximum conductor current) for activating the current sum monitor is set at address 8107 I FACTOR. Note Current sum monitoring can operate properly only when the residual current of the protected line is fed to the fourth current input (IN) of the relay. Note The connections of the ground paths and their adaption factors were set when configuring the general station data. These settings must be correct for the measured value monitoring to function properly. 191 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.11 Monitoring Functions Fuse Failure Monitor (FFM) Note The settings for the fuse failure monitor (address 5302 FUSE FAIL 3Vo) are to be selected so that reliable activation occurs if a phase voltage fails, but not such that false activation occurs during ground faults in a grounded network. Correspondingly address 5303 FUSE FAIL RESID must be set as sensitive as required (smaller than the smallest expected ground fault current). The function may be disabled in address 5301 FUSE FAIL MON., e.g. when performing asymmetrical tests. 2.11.1.7 Settings The table indicates region-specific default settings. Column C (configuration) indicates the corresponding secondary nominal current of the current transformer. Addr. Parameter C Setting Options Default Setting Comments 5301 FUSE FAIL MON. ON OFF OFF Fuse Fail Monitor 5302 FUSE FAIL 3Vo 10 .. 100 V 30 V Zero Sequence Voltage 5303 FUSE FAIL RESID 1A 0.10 .. 1.00 A 0.10 A Residual Current 5A 0.50 .. 5.00 A 0.50 A 8101 MEASURE. SUPERV OFF ON ON Measurement Supervision 8102 BALANCE V-LIMIT 10 .. 100 V 50 V Voltage Threshold for Balance Monitoring 8103 BAL. FACTOR V 0.58 .. 0.90 0.75 Balance Factor for Voltage Monitor 8104 BALANCE I LIMIT 1A 0.10 .. 1.00 A 0.50 A 5A 0.50 .. 5.00 A 2.50 A Current Threshold for Balance Monitoring 0.10 .. 0.90 0.50 Balance Factor for Current Monitor 1A 0.05 .. 2.00 A; 0.10 A 5A 0.25 .. 10.00 A; 0.50 A Summated Current Monitoring Threshold 0.00 .. 0.95 0.10 8105 BAL. FACTOR I 8106 I THRESHOLD 8107 I FACTOR SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 Summated Current Monitoring Factor 192 2 Functions 2.11.1.8 Information List No. Information Type of Information Comments 161 Fail I Superv. OUT Failure: General Current Supervision 162 Failure I OUT Failure: Current Summation 163 Fail I balance OUT Failure: Current Balance 167 Fail V balance OUT Failure: Voltage Balance 169 VT FuseFail>10s OUT VT Fuse Failure (alarm >10s) 170 VT FuseFail OUT VT Fuse Failure (alarm instantaneous) 171 Fail Ph. Seq. OUT Failure: Phase Sequence 175 Fail Ph. Seq. I OUT Failure: Phase Sequence Current 176 Fail Ph. Seq. V OUT Failure: Phase Sequence Voltage 197 MeasSup OFF OUT Measurement Supervision is switched OFF 6509 >FAIL:FEEDER VT SP >Failure: Feeder VT 6510 >FAIL: BUS VT SP >Failure: Busbar VT 2.11.2 Trip Circuit Supervision 74TC Devices 7SJ62/63/64 are equipped with an integrated trip circuit supervision. Depending on the number of available binary inputs (not connected to a common potential), supervision with one or two binary inputs can be selected. If the allocation of the required binary inputs does not match the selected supervision type, then a message to this effect is generated (74TC ProgFail"). Applications * When using two binary inputs, malfunctions in the trip circuit can be detected under all circuit breaker conditions. * When only one binary input is used, malfunctions in the circuit breaker itself cannot be detected. Prerequisites A condition for the use of trip circuit supervision is that the control voltage for the circuit breaker is at least twice the voltage drop across the binary input (VCTR > 2 * VBImin). Since at least 19 V are needed for the binary input, the supervision can only be used with a system control voltage of over 38 V. 193 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.11 Monitoring Functions 2.11.2.1 Description Supervision with Two Binary Inputs When using two binary inputs, these are connected according to Figure 2-62, parallel to the associated trip contact on one side, and parallel to the circuit breaker auxiliary contacts on the other. Figure 2-62 Principle of the trip circuit monitoring with two binary inputs Supervision with two binary inputs not only detects interruptions in the trip circuit and loss of control voltage, it also supervises the response of the circuit breaker using the position of the circuit breaker auxiliary contacts. Depending on the conditions of the trip contact and the circuit breaker, the binary inputs are activated (logical condition "H" in Table 2-10), or not activated (logical condition "L"). In healthy trip circuits the condition that both binary inputs are not actuated ("L") is only possible during a short transition period (trip contact is closed, but the circuit breaker has not yet opened.) A continuous state of this condition is only possible when the trip circuit has been interrupted, a short-circuit exists in the trip circuit, a loss of battery voltage occurs, or malfunctions occur with the circuit breaker mechanism. Therefore, it is used as monitoring criterion. Table 2-10 Condition table for binary inputs, depending on RTC and CB position No. Trip contact Circuit breaker 52a Contact 52b Contact BI 1 BI 2 1 Open Closed Closed Open H L 2 Open Open Open Closed H H 3 Closed Closed Closed Open L L 4 Closed Open Open Closed L H SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 194 2 Functions The conditions of the two binary inputs are checked periodically. A check takes place about every 600 ms. If three consecutive conditional checks detect an abnormality (after 1.8 s), an annunciation is reported (see Figure 2-63). The repeated measurements determine the delay of the alarm message and avoid that an alarm is output during short transition periods. After the malfunction in the trip circuit is cleared, the fault annunciation is reset automatically after the same time period. Figure 2-63 Supervision with One Binary Input Logic diagram of the trip circuit supervision with two binary inputs The binary input is connected according to the following figure in parallel with the associated trip contact of the protection relay. The circuit breaker auxiliary contact is bridged with a bypass resistor R. Figure 2-64 Trip circuit supervision with one binary input During normal operation, the binary input is activated (logical condition "H") when the trip contact is open and the trip circuit is intact, because the monitoring circuit is closed by either the 52a circuit breaker auxiliary contact (if the circuit breaker is closed) or through the bypass resistor R by the 52b circuit breaker auxiliary contact. Only as long as the trip contact is closed, the binary input is short circuited and thereby deactivated (logical condition "L"). If the binary input is continuously deactivated during operation, this leads to the conclusion that there is an interruption in the trip circuit or loss of control voltage. 195 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.11 Monitoring Functions The trip circuit monitor does not operate during system faults. A momentary closed tripping contact does not lead to a failure message. If, however, tripping contacts from other devices operate in parallel in the trip circuit, then the fault annunciation must be delayed (see also Figure 2-65). The state of the binary input is therefore, checked 500 times before an annunciation is sent. The state check takes place about every 600 ms, so that trip monitoring alarm is only issued in the event of an actual failure in the trip circuit (after 300 s). After the malfunction in the trip circuit is cleared, the fault annunciation is reset automatically after the same period. Figure 2-65 Logic diagram for trip circuit monitoring with one binary input The following figure shows the logic diagram for the message that can be generated by the trip circuit monitor, depending on the control settings and binary inputs. Figure 2-66 Message logic for the trip circuit monitor SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 196 2 Functions 2.11.2.2 Setting Notes General The function is only in effect and accessible if address 182 was set to either 2 Binary Inputs or to 1 Binary Input, and the appropriate number of binary inputs have been allocated for this purpose (refer to Section 2.1.1.2). The function may be turned ON at address 8201 FCT 74TC. If the allocation of the required binary inputs does not match the selected monitoring type, then a message to this effect is generated (74TC ProgFail"). If the trip circuit monitor is not to be used at all, then address 182 Disabled should be set. Further parameters are not needed. The message of a trip circuit interruption is delayed by a fixed amount of time. For two binary inputs, the delay is about 2 seconds, and for one binary input, the delay is about 300 s. Thus, it is ensured that the longest duration of a trip command is reliably bridged for a certain time and that an annunciation is only caused in case of a real fault occured within the trip command. Monitoring with One Binary Input Note: When using only one binary input (BI) for the trip circuit monitor, malfunctions, such as interruption of the trip circuit or loss of battery voltage are detected in general, but trip circuit failures while a trip command is active cannot be detected. Therefore, the measurement must take place over a period of time that bridges the longest possible duration of a closed trip contact. This is ensured by the fixed number of measurement repetitions and the time between the state checks. When using only one binary input, a resistor R is inserted into the circuit on the system side, instead of the missing second binary input. Through appropriate sizing of the resistor and depending on the system conditions, a lower control voltage can often be sufficient. Information for dimensioning resistor R is given in Chapter "Installation and Commissioning" under configuration instructions in Section "Trip Circuit Monitoring" 2.11.2.3 Settings Addr. 8201 Parameter FCT 74TC Setting Options ON OFF Default Setting Comments ON 74TC TRIP Circuit Supervision 2.11.2.4 Information List No. Information Type of Information Comments 6851 >BLOCK 74TC SP >BLOCK 74TC 6852 >74TC trip rel. SP >74TC Trip circuit superv.: trip relay 6853 >74TC brk rel. SP >74TC Trip circuit superv.: bkr relay 6861 74TC OFF OUT 74TC Trip circuit supervision OFF 6862 74TC BLOCKED OUT 74TC Trip circuit supervision is BLOCKED 6863 74TC ACTIVE OUT 74TC Trip circuit supervision is ACTIVE 6864 74TC ProgFail OUT 74TC blocked. Bin. input is not set 6865 74TC Trip cir. OUT 74TC Failure Trip Circuit 197 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.11 Monitoring Functions 2.11.3 Malfunction Responses of the Monitoring Functions In the following malfunction responses of monitoring equipment are clearly listed. 2.11.3.1 Description Malfunction Responses Depending on the type of malfunction discovered, an annunciation is sent, a restart of the processor system is initiated, or the device is taken out of service. After three unsuccessful restart attempts, the device is taken out of service. The live status contact operates to indicate the device is malfunctioning. In addition, if the internal auxiliary supply is present, the red LED "ERROR" lights up on the front cover and the green "RUN" LED goes out. If the internal power supply fails, then all LEDs are dark. Table 2-11 shows a summary of the monitoring functions and the malfunction responses of the relay. Table 2-11 Monitoring AC/DC supply voltage loss Summary of Malfunction Responses by the Protection Relay Possible Causes Malfunction Response Output All LEDs dark DOK2) drops out Device shutdown LED "ERROR" DOK2) drops out External (aux. voltage) inter- Device shutdown nal (power supply) Internal supply voltages Internal (power supply) Message (No.) Battery Internal (battery) Annunciation Fail Battery" (177) Hardware Watchdog Internal (processor failure) Device shutdown 1) LED "ERROR" DOK2) drops out Software watchdog Internal (processor failure) Restart attempt 1) LED "ERROR" DOK2) drops out Working memory ROM Internal (hardware) Relay aborts restart, Device shutdown LED blinks DOK2) drops out Program memory RAM Internal (hardware) During boot sequence LED "ERROR" DOK2) drops out During operation: Restart attempt 1) LED "ERROR" Settings Internal (hardware) Restart attempt 1) LED "ERROR" DOK2) drops out Sampling frequency Internal (hardware) Device shutdown LED "ERROR" DOK2) drops out Error in the I/O-board Internal (hardware) Device shutdown I/O-Board error" (178), DOK2) drops out LED "ERROR" Module error Internal (hardware) Device shutdown Error Board 1" to Error DOK2) drops out Board 7" (178 to 189), LED "ERROR" Internal auxiliary voltage 5 V Internal (hardware) Device shutdown Error 5V" (144), LED "ERROR" DOK2) drops out 0-V Monitoring Internal (hardware) Device shutdown Error 0V" (145), LED "ERROR" DOK2) drops out Internal auxiliary voltage -5 V Internal (hardware) Device shutdown Error -5V" (146), LED "ERROR" DOK2) drops out Offset monitoring Internal (hardware) Device shutdown Error Offset" (191) DOK2) drops out Internal supply voltages Internal (hardware) Device shutdown Error PwrSupply" (147), DOK2) drops out LED "ERROR" Current Sum Internal (measured value ac- Annunciation quisition) Failure I" (162) As allocated Current symmetry External (power system or current transformer) Annunciation Fail I balance" (163) As allocated Voltage symmetry External (power system or voltage transformer) Annunciation Fail V balance" (167) As allocated SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 198 2 Functions Monitoring Possible Causes Malfunction Response Message (No.) Output Voltage phase sequence External (power system or connection) Annunciation Fail Ph. Seq. V" (176) As allocated Current phase sequence External (power system or connection) Annunciation Fail Ph. Seq. I" (175) As allocated Fuse Failure Monitor External (voltage transform- Annunciation ers) VT FuseFail>10s" (169) As allocated VT FuseFail" (170) Trip circuit monitoring External (trip circuit or control voltage) Annunciation 74TC Trip cir." (6865) Calibration data fault Internal (hardware) Annunciation Alarm NO calibr" (193) As allocated 1) 2) Group Alarms 199 As allocated After three unsuccessful restarts, the device is taken out of service. DOK = "Device Okay" = Ready for service relay drops off, protection and control function are blocked. Certain messages of the monitoring functions are already combined to group alarms. A listing of the group alarms and their composition is given in the Appendix A.10. In this case, it must be noted that message 160 Alarm Sum Event" is only issued when the measured value monitoring functions (8101 MEASURE. SUPERV) are switched on. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.12 Ground Fault Protection 64, 67N(s), 50N(s), 51N(s) 2.12 Ground Fault Protection 64, 67N(s), 50N(s), 51N(s) Depending on the variant, the fourth current input of the multi-functional protection relays 7SJ62/63/64 is equipped either with a sensitive input transformer or a standard transformer for 1/5 A. In the first case, the active protective function is designed for ground fault detection in isolated or compensated systems due to its high sensitivity. It is not very suited for ground fault detection with large ground currents since the linear range is transcended at about 1.5 A at the sensitive ground fault detection relay terminals. If the relay is equipped with standard transformers for 1/5 A, also large currents can be detected correctly. Applications * Sensitive ground fault detection may be used in isolated or compensated systems to detect ground faults, to determine phases affected by ground faults, and to specify the direction of ground faults. * In solidly or low-resistance grounded systems, sensitive ground fault detection is used to detect high impedance ground faults. * This function can also be used as supplementary ground fault protection. 2.12.1 Voltage Element 64 The voltage element relies on a pickup initiated by the displacement voltage V0 or 3 * V0. Additionally, the faulty phase is determined. The displacement voltage V0 can be directly applied to the device, or the summary voltage 3 * V0 can be calculated by the device based on the three phase-to-ground voltages. In the latter case, the three voltage inputs must be connected to voltage transformers in a grounded-wye configuration (see also address 213 VT Connect. 3ph in Section 2.1.3). If the device is only provided with phase-to-phase voltages, it is not possible to calculate a displacement voltage from them. In this case the direction cannot be determined. If the displacement voltage is calculated, then: 3 * V0 = VA + VB + VC If the displacement voltage is directly applied to the device, then V0 is the voltage at the device terminals. It is not affected by parameter Vph / Vdelta (address 206). The displacement voltage is used both to detect a ground fault and to determine direction. When the voltage element picks up, a preset time delay must elapse before detection of the displacement voltage is reported to ensure measurement free quantities. The time delay can be configured (T-DELAY Pickup) and its factory setting is 1 s. Pickup initiated by the displacement voltage can be delayed (64-1 DELAY) for tripping. It is important to note that the total tripping time consists of the displacement voltage measurement time (about 60 ms) plus the pickup time delay (address 3111 T-DELAY Pickup) plus the tripping time delay (address 3112 64-1 DELAY). SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 200 2 Functions Determination of the Grounded Phase After the voltage element picks up due to detection of a displacement voltage, the grounded phase is identified, if possible. To do this, the individual phase-to-ground voltages are measured. Of course, this is only possible if three phase-to-ground voltages are obtained from voltage transformers connected in a grounded-wye configuration. If the voltage magnitude for any given phase is below the setting value VPh min that phase is detected as the grounded phase as long as the remaining phase-ground voltages are simultaneously above the setting value VPh max. The following figure shows the logic for determining the grounded phase. Figure 2-67 Determination of Grounded Phase 2.12.2 Current Elements 50Ns, 51Ns The current elements for ground faults operate with the magnitudes of the ground current. They only make sense where the magnitude of the ground current can be used to specify the ground fault. This may be the case on grounded systems (solid or lowresistance) or on electrical machines which are directly connected to the busbar of an isolated power system, when in case of a network ground fault the machine supplies only a negligible ground fault current across the measurement location, which must be situated between the machine terminals and the network, whereas in case of a machine ground fault the higher ground fault current produced by the total network is available. Ground current protection is mostly used as backup protection for high resistance ground faults in solid or low resistance grounded systems when main fault protection does not pickup. For ground fault detection, a two-step current/time characteristic can be set. Analog to the time overcurrent protection, the high-set current element is designated as 50Ns2 PICKUP and 50Ns-2 DELAY and is provided with a definite time characteristic. The overcurrent element may be operated with either a definite time delay (50Ns-1 PICKUP and 50Ns-1 DELAY) or with a user-defined characteristic (51Ns PICKUP 201 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.12 Ground Fault Protection 64, 67N(s), 50N(s), 51N(s) and 51NsTIME DIAL). Additionally, a current element with logarithmic inverse characteristic or logarithmic inverse characteristic with knee point is implemented. The characteristics of these current elements can be configured. Each of these elements may work directional or non-directional. Settable Dropout Times The pickup can be stabilized for ground fault protection with definite time curve by a settable dropout time. This facility comes into use in systems where intermittent faults occur. Combined with electromechanical relays, it allows different dropout responses to be adjusted and a time grading of numerical and electromechanical relays to be implemented. 2.12.3 Determination of Direction Characteristics When determining the sensitive ground fault direction it is not the current value that is crucial, but that part of the current which is perpendicular to an adjustable directional characteristic (axis of symmetry). As a prerequisite for determining the direction, the displacement voltage V0 must be exceeded as well as a configurable current part influencing the direction (active or reactive component). The following figure illustrates an example using a complex vector diagram in which the displacement voltage V0 is the reference magnitude of the real axis. The active part 3I0real of current 3I0 is calculated in reference to the displacement voltage V0 and compared with the setting value RELEASE DIRECT.. The example is therefore suited for determining the ground fault direction in grounded systems where 3I0 * cos is relevant. The directional limit lines are perpendicular to axis 3I0real. Figure 2-68 Directional characteristic for cos--measurement The directional limit lines may be rotated by a correction angle (address PHI CORRECTION) up to 45. Therefore, in grounded systems it is possible, e.g. to increase sensitivity in the resistive-inductive range with a rotation of -45, or in case of electric machines in busbar connection in the resistive-capacitive range with a rotation of +45 (see the following Figure). Furthermore the directional limit lines may be rotated by 90 to determine ground faults and their direction in isolated systems. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 202 2 Functions Figure 2-69 Method of Directional Measurement Directional characteristic for cos--measurement Fault direction is calculated with the zero sequence values from the ground current 3I0 and displacement voltage V0 or 3 * V0. With these quantities, ground active power and ground reactive power is calculated. The used calculation algorithm filters the measured values so that it is highly accurate and insensitive to higher harmonics (particularly the 3rd and 5th harmonics - which are often present in zero sequence currents). Direction determination relies on the sign of active and reactive power. Since active and reactive components of the current - not the power - are relevant for pickup, current components are calculated from the power components. When determining the ground fault direction the active or reactive components of the ground current in reference to the displacement voltage as well as the direction of the active and reactive power are evaluated. For measurements sin the following applies * Ground fault (forward direction), if Q0 < 0 and 3I0reactive > setting value (RELEASE DIRECT.), * Ground fault (reverse direction), if Q0 > 0 and 3I0reactive > setting value (RELEASE DIRECT.). For measurements cos (for resonant-grounded systems) the following applies * Ground fault (forward direction), if P0 > 0 and 3I0reactive > setting value (RELEASE DIRECT.), * Ground fault (reverse direction), if P0 < 0 and 3I0reactive > setting value (RELEASE DIRECT.). If PHI CORRECTION unequal 0, the angle of the symmetrie lines is calculated by adding up active and reactive power components. 203 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.12 Ground Fault Protection 64, 67N(s), 50N(s), 51N(s) Application Instructions In systems with isolated starpoint, ground fault current flows as capacitive current from healthy lines to the location of the ground fault via the measuring point. The capacitive reactive power is thus relevant for the direction. In networks with arc suppression coils, the Petersen coil superimposes a corresponding inductive current on the capacitive ground fault current when a ground fault occurs, so that the capacitive current at the point of fault is compensated. Depending on the measuring point in the system the resultant measured current may be inductive or capacitive. Therefore, the reactive current is not suited for direction determination of the ground current. In this case, only the ohmic (active) residual current which results from the losses of the Petersen coil can be used for directional determination. The residual current of the ground fault is only about some per cent of the capacitive ground fault current. Please note that depending on the mounting location of the device, the real component of the current may only be a small fraction of the reactive current component (in extreme cases down to 1/50 th). The accuracy of the calculation algorithm which is extremely high is not sufficient if the instrument transformer is not able to transmit the primary values accuratetly. The measuring input of the protection relay for high-sensitive ground fault detection is especially calibrated to these concerns and allows an extremely high sensitivity for the direction determination of the residual wattmetric current. In order to make use of this sensitivity, we recommend cable core balance current transformers for ground fault detection in resonant grounded systems. Furthermore, the angle error of the cable core balance current transformer can be compensated in the device. Since the angle error is non-linear, this is achieved by entering two operating points of the angle error curve of the transformer. The device then calculates the error curve with sufficient accuracy. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 204 2 Functions 2.12.4 Logic The following figure illustrates a state logic of the sensitive ground fault protection. Ground fault detection can be switched ON or OFF or set to Alarm Only (address 3101). When ground fault protection is ON, tripping is possible. The pickup of the displacement voltage V0 starts the ground fault recording. As the pickup of the V0 element drops out, fault recording is terminated. In mode Alarm Only, ground faults are recorded in a separate log file for ground faults. In this operating mode, the annunciation 303 sens Gnd flt" opens and closes the log file for ground faults and the present fault number is included (see logic diagrams from Figures 2-71 and 2-72). The entire function may be blocked via binary input. Switching off or blocking means the measurement logic is deactivated. Therefore, time delays and pickup messages are reset. All stages can be blocked individually via binary inputs. In this case pickup and, if possible, direction and grounded phase will still be reported, however, tripping does not take place since the time elements are blocked. Figure 2-70 Activation of the sensitive ground current protection Generation of a pickup message, for both current elements, is dependent on the direction selection for each element and the setting of parameters 3130 PU CRITERIA. If the element is set to Non-Directional and parameter PU CRITERIA = Vgnd OR INs, a pickup message is generated as soon as the current threshold is exceeded, irrespective of the status of the V0 element. If, however, the setting of parameter PU CRITERIA is Vgnd AND INs, the V0-element must have picked up also for non-directional mode. But, if a direction is programmed, the current element must be picked up and the direction determination results must be present to generate a message. Once again, a condition for valid direction determination is that the voltage element V0 be picked up. Setting at address PU CRITERIA specifies, whether a fault is generated by means of the AND-function or the OR-combination of displacement voltage and pickup of the ground current. The former may be advantageous if the pickup setting of voltage element V0 was chosen to be very low. 205 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.12 Ground Fault Protection 64, 67N(s), 50N(s), 51N(s) Figure 2-71 Logic diagram of the 64 element and determination of direction SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 206 2 Functions Figure 2-72 207 Logic diagram of the INs elements SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.12 Ground Fault Protection 64, 67N(s), 50N(s), 51N(s) Pickup of the definite time elements can be stabilized by setting the dropout time 3121 50Ns T DROP-OUT. This time is started and maintains the pickup condition if the current falls below the threshold. The function thus does not drop out instantaneously. The trip delay time continues in the meantime. After the dropout delay time has elapsed, the pickup is reported OFF and the trip delay time is reset unless the threshold has been violated again. If the threshold is exceeded again while the dropout delay time is still running, it will be cancelled. The trip delay time continues however. If the threshold is still exceeded after the time has elapsed, a trip will be initiated immediately. If the threshold violation then no longer exists, there will be no response. If the threshold is exceeded again after the trip command delay time has elapsed and while the dropout delay time is still running, a trip will be initiated at once. 2.12.5 Ground Fault Location (in isolated systems) Application Example Directional determination can often be used to locate ground faults. In radial systems, locating the ground fault is relatively simple. Since all feeders from a common busbar (Figure 2-73) deliver a capacitive charging current, nearly the total ground fault current of the system is available at the measuring point on the faulty line in the isolated system. In resonant-grounded system it is the residual wattmetric current of the Petersen Coil that flows via the measuring point. Therefore, on the faulty cables a clear "forward" decision is made whereas in other feeders either "reverse" direction is sent back or no measurement is carried out in case ground current is too low. Definitely the faulty line can be determined clearly. Figure 2-73 Location of ground faults in a radial network In meshed or ring systems, the measuring points of the faulty line also may detect the maximum ground fault current (residual current). Only in this line, "forward" direction is signaled at both ends (Figure 2-74). However, also the rest of the direction indications in the system may be useful for ground fault detection. Some indications may not be output when ground current is too low. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 208 2 Functions Figure 2-74 Determination of the ground fault location basing on directional indicators in the meshed system 2.12.6 Setting Notes General Settings The operating mode of the protective function is configured at address 131 Sens. Gnd Fault (see Section 2.1.1). If address Sens. Gnd Fault = Definite Time, then only the settings for the definite-time elements are available. If the setting is Sens. Gnd Fault = Log. inverse A, a logarithmic inverse characteristic is available. If the setting is Sens. Gnd Fault = Log. Inverse B, a logarithmic inverse characteristic with knee point is active. Alternatively, user-defined characteristic can be used when setting Sens. Gnd Fault = User Defined PU. The superimposed high-set element 50Ns-2 is available in all these cases. If the function is not required, Disabled is set. Address 213 VT Connect. 3ph specifies how the voltage transformers are connected (phase-ground or phase-phase). Furthermore, adaption factor Vph / Vdelta for displacement voltage are properly set in address 206, primary and secondary nominal transformer current in the ground path are properly set in addresses 217 and 218. Sensitive ground fault detection may be switched ON or OFF or to Alarm Only in address 3101 Sens. Gnd Fault. If sensitive ground fault protection is switched ON, both tripping and message reporting is possible. The ground fault is detected and reported only when the displacement voltage was present for at least the time T-DELAY Pickup (address 3111). Address 3130 PU CRITERIA specifies whether ground fault detection is enabled only for pickups of V0 and INs (Vgnd AND INs) or as soon as one of the two has picked up (Vgnd OR INs). A two-stage current/time characteristic may be set at addresses 3113 through 3120. Each of these elements may be directional or non-directional. These elements operate with the ground current magnitude. They only make sense where the magnitude of the ground current and maybe the direction can be used to specify the ground fault. This may be the case on grounded systems (solid or low-resistant) or on electrical machines which are directly connected to the busbar of an ungrounded power system, when in case of a network ground fault the machine supplies only a negligible ground fault current across the measurement location, which must be situated between the machine terminals and the network, whereas in case of a machine ground fault the total ground fault current produced by the total network is available. 209 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.12 Ground Fault Protection 64, 67N(s), 50N(s), 51N(s) 50Ns-2 Element (Definite Time) Similar to the time overcurrent protection function the high set element is named 50Ns-2 PICKUP (address 3113). It is delayed with 50Ns-2 DELAY (address 3114) and may be set to generate a message or to trip. The latter is only possible if address 3101 Sens. Gnd Fault is set to ON. 50Ns-1 Element (Definite Time) The definite tripping characteristic 50Ns-1 is set with addresses 3117 and 3118 (address 131 Sens. Gnd Fault = Definite Time). Pickup Stabilization (Definite Time) Pickup of the definite time elements can be stabilized by means of a configurable dropout time. This dropout time is set in 3121 50Ns T DROP-OUT. 51Ns Element (Inverse Time) The inverse tripping characteristic 51N-TOC is set with addresses 3119 and 3120 (address 131 Sens. Gnd Fault = User Defined PU). Logarithmic Inverse characteristic (Inverse Time) The logarithmic inverse characteristic (see Figure 2-75) is set in parameters 3119 51Ns PICKUP, 3141 51Ns Tmax, 3140 51Ns Tmin, 3142 51Ns TIME DIAL and 3143 51Ns Startpoint. 51Ns Tmin and 51Ns Tmax define the tripping time range. The slope of the curve is defined in 3142 51Ns TIME DIAL. 51Ns PICKUP is the reference value for all current values with 51Ns Startpoint representing the beginning of the curve, i.e. the lower operating range on the current axis (related to 51Ns PICKUP). This factor is preset to the value 1.1, analogous to the other inverse time curves. This factor can also be set to 1.0 since in logarithmic inverse curves the tripping time on a current value, which is identical to the specified pickup threshold, does not go towards infinity, but has a finite time value. Figure 2-75 Trip-time characteristics of the inverse-time ground fault protection 51Ns with logarithmic inverse characteristic Logarithmic inverse Note: t = 51Ns MAX. TIME DIAL - 51Ns TIME DIAL*ln(I/51Ns PICKUP) For I/51Ns PICKUP > 35 the time applies for I/51Ns PICKUP = 35 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 210 2 Functions Logarithmic Inverse characteristic with Knee Point (inverse time) The logarithmic inverse characteristic with knee point (see figure 2-76) is set by means of the parameters 3119 51Ns PICKUP, 3127 51Ns I T min, 3128 51Ns I T knee, 3132 51Ns TD, 3140 51Ns T min and 3141 51Ns T max. 51Ns T min and 51Ns T max define the range of the tripping time where 51Ns T max is assigned to the current threshold 51Ns PICKUP and 51Ns T min to the current threshold 51Ns I T min. The knee-point time 51Ns T knee specifies the tripping time in the transition point of two characteristic segments with different slope. The transition point is defined by the current threshold 51Ns I T knee. 51Ns PICKUP is the minimum pickup threshold for the ground-fault pickup current of the overcurrent element. The tripping time will assume a constant value after reaching a maximum secondary current of 1.4 A at the latest. The parameter 51Ns TD serves as time multiplier for the tripping time. Figure 2-76 User Defined characteristics (Inverse Time) Trip-time characteristics of the inverse-time ground fault protection 51Ns with logarithmic inverse characteristic with knee point (example for 51Ns = 0.004 A) If a user-defined characteristic is configured at address 131, Sens. Gnd Fault User Defined PU, it should be noted that there is a safety factor of 1.1 between pickup and setting value - as is standard for inverse curves. This means that pickup will only be initiated when current of 1.1 times the setting value flows. Entry of the value pair (current and time) is a multiple of the settings at addresses 3119 51Ns PICKUP and 3120 51NsTIME DIAL. Therefore, it is recommended that these addresses are initially set to 1.00 for simplicity. Once the curve is entered, the settings at addresses 3119 and/or 3120 may be modified if necessary. The default setting of current values is . They are, therefore, not enabled -- and no pickup or tripping of these protective functions will occur. Up to 20 pairs of values (current and time) may be entered at address 3131 M.of PU TD. The device then approximates the characteristic, using linear interpolation. 211 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.12 Ground Fault Protection 64, 67N(s), 50N(s), 51N(s) The following must be observed: * The value pairs should be entered in increasing sequence. Fewer than 20 pairs is also sufficient. In most cases, about 10 pairs is sufficient to define the characteristic accurately. A value pair which will not be used has to be made invalid by entering "" for the threshold! The user must ensure the value pairs produce a clear and constant characteristic. The current values entered should be those from Table 2-3, along with the matching times. Deviating values MofPU (multiples of PU-values) are rounded. This, however, will not be indicated. Currents less than the smallest current value entered will not lead to an extension of the tripping time. The pickup curve (see Figure 2-77) continues, from the smallest current point parallel to the current axis. Currents greater than the highest current value entered will not lead to a reduction of the tripping time. The pickup curve (see Figure 2-77) continues, from the largest current point parallel to the current axis. Table 2-12 Preferential values of standardized currents for user-defined tripping curves MofPU = 1 to 1.94 MofPU = 5 to 7.75 MofPU = 8 to 20 1.50 2.00 3.50 5.00 6.50 1.06 1.56 2.25 3.75 5.25 6.75 9.00 16.00 1.13 1.63 2.50 4.00 5.50 7.00 10.00 17.00 1.19 1.69 2.75 4.25 5.75 7.25 11.00 18.00 1.25 1.75 3.00 4.50 6.00 7.50 12.00 19.00 1.31 1.81 3.25 4.75 6.25 7.75 13.00 20.00 1.38 1.88 1.44 1.94 Figure 2-77 Determination of Ground-Faulted Phase MofPU = 2 to 4.75 1.00 8.00 15.00 14.00 Use of a user-defined characteristic The ground-faulted phase may be identified in an ungrounded or resonant-grounded system, if the device is supplied by three voltage transformers connected in a grounded-wye configuration. The phase in which the voltage lies below setting VPH MIN at address 3106 is identified as the faulty phase as long as the other two phase voltages simultaneously exceed the setting VPH MAX at address 3107. The setting VPH MIN must be set less than the minimum expected operational phase-to-ground voltage. A typical setting for this address would be 40 V. Setting VPH MAX must be greater than SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 212 2 Functions the maximum expected operational phase-to-ground voltage, but less than the minimum expected operational phase-to-phase voltage. For VNom = 100 V, approximately 75 V is a typical setting. These settings have no significance in a grounded system. Displacement Voltage V0 Displacement voltage 64-1 VGND (address 3108 or 3109) or 64-1 VGND (address 3110) is used to pick up ground fault detection. At the same time, pickup of the voltage element is a condition for initiation of directional determination. Depending on the setting at address 213 VT Connect. 3ph, only the applicable threshold address 3108 64-1 VGND, 3109 64-1 VGND or 3110 64-1 VGND is accessible: That is, if two phase-to-phase voltages and the displacement voltage V0 are supplied to the device, the measured displacement voltage is used directly for ground fault recognition. The threshold for V0 is set at address 3108 (7SJ62/63) or 3109 (7SJ64), where a more sensitive setting can be made than with a calculated displacement voltage. The upper setting threshold for 7SJ64 is higher than for 7SJ62/63 (see Technical Data). Please note that with phase-to-phase voltage V0, the factor (in normal case = 1.73; see also Section 2.1.3.2) specified with parameter 206 Vph / Vdelta is used. For display of parameter 3108 64-1 VGND or 3109 64-1 VGND in primary values, the following conversion formula applies: If three phase-to-ground voltages are connected to the device, the displacement voltage 3 * V0 is calculated from the momentary values of phase-to-ground voltages, and address 3110 is where the threshold is to be set. For the display of the parameters 3110 in primary values, the following applies: If secondary values of (for example) parameter 3109 and 3110 are set the same, their primary values differ by the adaptation factor Vph / Vdelta. Example: 213 Parameter 202 Vnom PRIMARY = 12 kV Parameter 203 Vnom SECONDARY = 100 V Parameter 206 Vph / Vdelta = 1.73 Parameter 213 VT Connect. 3ph = Vab, Vbc, VGnd Parameter 3109 64-1 VGND = 40 V SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.12 Ground Fault Protection 64, 67N(s), 50N(s), 51N(s) When changing to primary values, the following applies: Motor with the parameterization: Parameter 213 VT Connect. 3ph = Van, Vbn, Vcn Parameter 3110 64-1 VGND = 40 V When changing to primary values, the following applies: With regard to a ground fault in a ungrounded or resonant-grounded system, nearly the entire displacement voltage appears at the device terminals, therefore the pickup setting is not critical, and typically lies between 30 V and 60 V (for 64-1 VGND with a standard V0-connection) or 50 V and 100 V (for 64-1 VGND). Large fault resistances may require higher sensitivity (i.e. a lower pickup setting). With regard to a grounded system, a more sensitive (lower) pickup value may be set, but it must be above the maximum anticipated displacement voltage during normal (unbalanced) system operation. Trip Time Delay Pickup of just the voltage element may initiate time delayed tripping assuming that ground fault detection is configured to perform tripping (address 3101 Sens. Gnd Fault = ON) and moreover address 3130 PU CRITERIA is configured Vgnd OR INs. The tripping delay is then set at address 3112 64-1 DELAY. It is important to note that the total tripping time consists of the displacement voltage measurement time (about 50 ms) plus the pickup time delay (address 3111 T-DELAY Pickup) plus the tripping time delay (address 3112 64-1 DELAY). Determination of Direction Addresses 3115 to 3126 are for direction determination. The direction of the definite high-set element 67Ns-2 is set at address 3115 67Ns-2 DIRECT and may be configured Forward or Reverse or Non-Directional, i.e. to both directions. The direction of the definite time high-set element 67Ns-1 can be set at address 3122 67Ns-1 DIRECT. = Forward or Reverse or Non-Directional, i.e. to both directions. Current value RELEASE DIRECT. (address 3123) is the release threshold for directional determination. It is based on the current components which are perpendicular to the directional limit lines. The position of the directional limit lines themselves are based on the settings entered at addresses 3124 and 3125. The following is generally valid for determination of direction during ground faults: The pickup current INs dir (=RELEASE DIRECT. address 3123) must be set as high as possible to avoid a false pickup of the device provoked by asymmetrical currents in the system and by current transformers (especially in a Holmgreen-connection). If direction determination is used in conjunction with one of the current elements discussed above (50Ns-1 PICKUP, addresses 3117 ff, or 51Ns PICKUP, addresses 3119 ff), a value for address RELEASE DIRECT. is only significant if it is less than or equal to the pickup value mentioned above. A corresponding message (reverse, forward, or undefined) is issued upon direction determination. To avoid chatter for this message resulting from sharply-varying ground fault currents, a dropout delay RESET DELAY, entered at address 3126, is initiated SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 214 2 Functions when directional determination drops out, and the message is held for this period of time. When address 3124 PHI CORRECTION is set to 0.0, then the setting in address 3125 signifies the following: * MEAS. METHOD = COS the resistive component of the ground current with respect to the displacement voltage is most relevant for the current value RELEASE DIRECT. (3I0dir) MEAS. METHOD = SIN the reactive (capacitive) component of the ground current with respect to the displacement voltage is most relevant for the current value RELEASE DIRECT. (3I0dir) (see Figure 2-78). Figure 2-78 Directional characteristic for sin--measurement * In address 3124 PHI CORRECTION the directional line, in this respect, may be rotated within the range 45. Figure "Directional characteristic for cos--measurement" in the functional description of the sensitive ground fault detection gives an example regarding this topic. Ungrounded System 215 In an ungrounded system with a ground fault on a cable, capacitive ground currents of the galvanically connected system flow via the measuring point, apart from the ground current generated on the faulty line, which flows directly via the fault location (i.e. not via the measuring point). A setting equal to about half of this ground current is to be selected. The measurement type should be SIN , since capacitive ground current is most relevant here. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.12 Ground Fault Protection 64, 67N(s), 50N(s), 51N(s) Resonant-grounded System In a resonant-grounded system, directional determination on the occurrence of a ground fault results more difficult since the small residual wattmetric current for measurement is usually dwarfed by a larger reactive current (be it capacitive or inductive) which is much larger. Therefore, depending on the system configuration and the position of the arc-compensating coil, the total ground current supplied to the device may vary considerably in its values with regard to magnitude and phase angle. The relay, however, must evaluate only the active component of the ground fault current, that is, INs cos . This demands extremely high accuracy, particularly with regard to phase angle measurement of all instrument transformers. Furthermore, the device must not be set to operate too sensitive. When applying this function in resonant-grounded systems, a reliable direction determination can only be achieved by connecting cable core balance current transformers. Here the following rule of thumb applies: Set pickup values to about half of the expected measured current, thereby considering only the residual wattmetric current. Residual wattmetric current is mainly due to losses of the Petersen coil. Here, the COS measuring type is used since the resistive residual wattmetric current is relevant. Grounded System In grounded systems, a value is set below the minimum anticipated ground fault current. It is important to note that INs dir (current value RELEASE DIRECT.) only detects the current component that is perpendicular to the directional limit line defined at addresses 3124 and 3125. COS is the type of measurement used, and the correction angle is set to -45, since the ground fault current is typically resistive-inductive (right section of Figure "Directional characteristic for cos--measurement in the functional description of the sensitive ground fault detection). Electrical Machines One may set the value COS for the measurement type and use a correction angle of +45 for electrical motors supplied from a busbar in an ungrounded system, since the ground current is often composed of an overlap of the capacitive ground current from the system and the resistive current of the load resistance (Figure "Directional characteristic for cos--measurement" in the functional description of the sensitive ground fault detection, left part). Angular Error Compensation (CTs) The high reactive component in a resonant grounded system and the inevitable air gap of the cable core balance current transformer often require the angle error of the cable core balance current transformer to be compensated. In addresses 3102 to 3105 the maximum angle error CT Err. F1 and the associated secondary current CT Err. I1 as well as another operating point CT Err. F2/CT Err. I2 are set for the actually connected burden. The device thus approximates the transformation characteristic of the transformer with considerable accuracy. In ungrounded or grounded systems angle compensation is not required. Note Regarding Settings List for Sensitive Ground Fault Detection In devices with sensitive ground fault input, which is independent of the nominal current rating of the device, settings may in general also be entered as primary values under consideration of the current transformer ratio. However, problems related to the resolution of the pickup currents can occur when very small settings and small nominal primary currents are given. The user is therefore encouraged to enter settings for the sensitive ground fault detection in secondary values. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 216 2 Functions 2.12.7 Settings Addresses which have an appended "A" can only be changed with DIGSI, under "Display Additional Settings". The table indicates region-specific default settings. Column C (configuration) indicates the corresponding secondary nominal current of the current transformer. Addr. Parameter C Setting Options Default Setting Comments 3101 Sens. Gnd Fault OFF ON Alarm Only OFF (Sensitive) Ground Fault 3102 CT Err. I1 0.001 .. 1.600 A 0.050 A Current I1 for CT Angle Error 3102 CT Err. I1 1A 0.05 .. 35.00 A 1.00 A 5A 0.25 .. 175.00 A 5.00 A Current I1 for CT Angle Error 3103 CT Err. F1 0.0 .. 5.0 0.0 CT Angle Error at I1 3104 CT Err. I2 0.001 .. 1.600 A 1.000 A Current I2 for CT Angle Error 3104 CT Err. I2 1A 0.05 .. 35.00 A 10.00 A 5A 0.25 .. 175.00 A 50.00 A Current I2 for CT Angle Error 3105 CT Err. F2 0.0 .. 5.0 0.0 CT Angle Error at I2 3106 VPH MIN 10 .. 100 V 40 V L-Gnd Voltage of Faulted Phase Vph Min 3107 VPH MAX 10 .. 100 V 75 V L-Gnd Voltage of Unfaulted Phase Vph Max 3108 64-1 VGND 1.8 .. 200.0 V 40.0 V 64-1 Ground Displacement Voltage 3109 64-1 VGND 1.8 .. 170.0 V 40.0 V 64-1 Ground Displacement Voltage 3110 64-1 VGND 10.0 .. 225.0 V 70.0 V 64-1 Ground Displacement Voltage 3111 T-DELAY Pickup 0.04 .. 320.00 sec; 1.00 sec Time-DELAY Pickup 3112 64-1 DELAY 0.10 .. 40000.00 sec; 10.00 sec 64-1 Time Delay 3113 50Ns-2 PICKUP 0.001 .. 1.500 A 0.300 A 50Ns-2 Pickup 3113 50Ns-2 PICKUP 1A 0.05 .. 35.00 A 10.00 A 50Ns-2 Pickup 5A 0.25 .. 175.00 A 50.00 A 3114 50Ns-2 DELAY 0.00 .. 320.00 sec; 1.00 sec 50Ns-2 Time Delay 3115 67Ns-2 DIRECT Forward Reverse Non-Directional Forward 67Ns-2 Direction 3117 50Ns-1 PICKUP 0.001 .. 1.500 A 0.100 A 50Ns-1 Pickup 3117 50Ns-1 PICKUP 1A 0.05 .. 35.00 A 2.00 A 50Ns-1 Pickup 5A 0.25 .. 175.00 A 10.00 A 3118 50Ns-1 DELAY 0.00 .. 320.00 sec; 2.00 sec 50Ns-1 Time delay 3119 51Ns PICKUP 0.001 .. 1.400 A 0.100 A 51Ns Pickup 217 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.12 Ground Fault Protection 64, 67N(s), 50N(s), 51N(s) Addr. Parameter 3119 51Ns PICKUP 3119 51Ns PICKUP C Setting Options Default Setting Comments 0.003 .. 0.500 A 0.004 A 51Ns Pickup 1A 0.05 .. 4.00 A 1.00 A 51Ns Pickup 5A 0.25 .. 20.00 A 5.00 A 3120 51NsTIME DIAL 0.10 .. 4.00 sec; 1.00 sec 51Ns Time Dial 3121A 50Ns T DROP-OUT 0.00 .. 60.00 sec 0.00 sec 50Ns Drop-Out Time Delay 3122 67Ns-1 DIRECT. Forward Reverse Non-Directional Forward 67Ns-1 Direction 3123 RELEASE DIRECT. 0.001 .. 1.200 A 0.010 A Release directional element 3123 RELEASE DIRECT. 1A 0.05 .. 30.00 A 0.50 A 5A 0.25 .. 150.00 A 2.50 A Release directional element 3124 PHI CORRECTION -45.0 .. 45.0 0.0 Correction Angle for Dir. Determination 3125 MEAS. METHOD COS SIN COS Measurement method for Direction 3126 RESET DELAY 0 .. 60 sec 1 sec Reset Delay 3127 51Ns I T min 0.003 .. 1.400 A 1.333 A 51Ns Current at const. Time Delay T min 3127 51Ns I T min 1A 0.05 .. 20.00 A 15.00 A 5A 0.25 .. 100.00 A 75.00 A 51Ns Current at const. Time Delay T min 0.003 .. 0.650 A 0.040 A 51Ns Current at Knee Point 1A 0.05 .. 17.00 A 5.00 A 5A 0.25 .. 85.00 A 25.00 A 51Ns Current at Knee Point 3128 51Ns I T knee 3128 51Ns I T knee 3129 51Ns T knee 0.20 .. 100.00 sec 23.60 sec 51Ns Time Delay at Knee Point 3130 PU CRITERIA Vgnd OR INs Vgnd AND INs Vgnd OR INs Sensitive Ground Fault PICKUP criteria 3131 M.of PU TD 1.00 .. 20.00 MofPU; 0.01 .. 999.00 TD 3132 51Ns TD 0.05 .. 1.50 0.20 51Ns Time Dial 3140 51Ns Tmin 0.00 .. 30.00 sec 1.20 sec 51Ns Minimum Time Delay 3140 51Ns T min 0.10 .. 30.00 sec 0.80 sec 51Ns Minimum Time Delay 3141 51Ns Tmax 0.00 .. 30.00 sec 5.80 sec 51Ns Maximum Time Delay 3141 51Ns T max 0.50 .. 200.00 sec 93.00 sec 51Ns Maximum Time Delay (at 51Ns PU) 3142 51Ns TIME DIAL 0.05 .. 15.00 sec; 1.35 sec 51Ns Time Dial 3143 51Ns Startpoint 1.0 .. 4.0 1.1 51Ns Start Point of Inverse Charac. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 Multiples of PU Dial Time- 218 2 Functions 2.12.8 Information List No. Information Type of Information Comments 1201 >BLOCK 64 SP >BLOCK 64 1202 >BLOCK 50Ns-2 SP >BLOCK 50Ns-2 1203 >BLOCK 50Ns-1 SP >BLOCK 50Ns-1 1204 >BLOCK 51Ns SP >BLOCK 51Ns 1207 >BLK 50Ns/67Ns SP >BLOCK 50Ns/67Ns 1211 50Ns/67Ns OFF OUT 50Ns/67Ns is OFF 1212 50Ns/67Ns ACT OUT 50Ns/67Ns is ACTIVE 1215 64 Pickup OUT 64 displacement voltage pick up 1217 64 TRIP OUT 64 displacement voltage element TRIP 1221 50Ns-2 Pickup OUT 50Ns-2 Pickup 1223 50Ns-2 TRIP OUT 50Ns-2 TRIP 1224 50Ns-1 Pickup OUT 50Ns-1 Pickup 1226 50Ns-1 TRIP OUT 50Ns-1 TRIP 1227 51Ns Pickup OUT 51Ns picked up 1229 51Ns TRIP OUT 51Ns TRIP 1230 Sens. Gnd block OUT Sensitive ground fault detection BLOCKED 1264 IEEa = VI Corr. Resistive Earth current 1265 IEEr = VI Corr. Reactive Earth current 1266 IEE = VI Earth current, absolute Value 1267 VGND, 3Vo VI Displacement Voltage VGND, 3Vo 1271 Sens.Gnd Pickup OUT Sensitive Ground fault pick up 1272 Sens. Gnd Ph A OUT Sensitive Ground fault picked up in Ph A 1273 Sens. Gnd Ph B OUT Sensitive Ground fault picked up in Ph B 1274 Sens. Gnd Ph C OUT Sensitive Ground fault picked up in Ph C 1276 SensGnd Forward OUT Sensitive Gnd fault in forward direction 1277 SensGnd Reverse OUT Sensitive Gnd fault in reverse direction 1278 SensGnd undef. OUT Sensitive Gnd fault direction undefined 16029 51Ns BLK PaErr OUT Sens.gnd.flt. 51Ns BLOCKED Setting Error 219 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.13 Intermittent Ground Fault Protection 2.13 Intermittent Ground Fault Protection A typical characteristic of intermittent ground faults is that they often disappear automatically to strike again after some time. They can last between a few milliseconds and several seconds. This is why such faults are not detected at all or not selectively by the ordinary time overcurrent protection. If pulse durations are extremely short, not all protection devices in a short-circuit path may pick up; selective tripping is thus not ensured. Due to the time delay of the overcurrent protection function such faults are too short to initiate shutdown of the faulted cable. Only when they have become permanent such ground faults can be removed selectively by the short-circuit protection. But such intermittent ground faults already bear the risk of causing thermal damage to equipment. This is why devices 7SJ62/63/64 feature a protective function that is able to detect such intermittent ground faults and accumulates their duration. If within a certain time their sum reaches a settable value, the thermal load limit has been reached. If the ground faults are distributed over a long period of time or if the ground fault goes off and does not re-ignite after some time, the equipment under load is expected to cool down. Tripping is not necessary in this case. Applications * Protection from intermittent ground faults which occur, e.g. in cables due to poor insulation or water ingress in cable joints. 2.13.1 Description Acquisition of Measured Quantities The intermittent ground fault can either be detected via the ordinary ground current input (IN), the sensitive ground current input (INS), or it is calculated from the sum of the three phase currents (3 I0). Unlike the overcurrent protection which uses the fundamental wave, the intermittent ground fault protection creates the r.m.s. value of this current and compares it to a settable threshold Iie>. This method accounts for higher order harmonics contents (up to 400 Hz) and for the direct component since both factors contribute to the thermal load. Pickup/Tripping When the pickup threshold Iie> is exceeded, a pickup message (IIE Fault det", see Figure 2-79) is issued. The pickups are also counted; as soon as the counter content has reached the value of parameter Nos.det., the message Intermitt.EF" is issued. A stabilized pickup is obtained by prolonging the pickup message IIE Fault det" by a settable time T-det.ext.. This stabilization is especially important for the coordination with existing static or electromechanical overcurrent relays. The duration of the stabilized pickups IIE stab.Flt" is summated with an integrator T-sum det.. If the accumulated pickup time reaches a settable threshold value, a corresponding message is generated (IEF Tsum exp."). Tripping takes place, however, only while a ground fault is present (message IEF Trip"). The trip command is maintained during the entire minimum tripping time specified for the device, even if the ground fault is of short duration. After completion of the tripping command all memories are reset and the protection resumes normal condition. The (much longer) resetting time T-sum det. (message T-reset) is launched simultaneously with IEF Tres run." when a ground fault occurs. Unlike T-sum det. each new ground fault resets this time to its initial value and it expires anew. If T-reset expires and no new ground fault is recorded during that time, all memories SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 220 2 Functions are reset and the protection returns to its quiescent state. T-reset thus determines the time during which the next ground fault must occur to be processed yet as intermittent ground fault in connection with the previous fault. A ground fault that occurs later will be considered a new fault event. The message IIE Fault det" will be entered in the fault log and reported to the system interface only until the message Intermitt.EF" is issued. This prevents a burst of messages. If the message is allocated to an LED or a relay, this limitation does not apply. This is accomplished by doubling the message (message numbers 6924, 6926). Interaction with the Automatic Reclosure Function Automatic reclosure is not an effective measure against intermittent ground faults as the function only trips after repeated detection of a fault or after expiration of the summation monitoring time T-sum det. and besides this, its basic design is to prevent thermal overload. For these reasons, the intermittent ground fault protection is not implemented as starting feature of the automatic reclosing function. Interaction with Breaker Failure Protection A pickup that is present when the time delay TRIP-Timer has expired is interpreted by the breaker failure protection as a criterion for a tripping failure. Since permanent pickup is not ensured after a tripping command by the intermittent ground fault protection, cooperation with the breaker failure protection is not sensible. Therefore, this function is not activated by the intermittent ground fault protection. 221 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.13 Intermittent Ground Fault Protection Logic Diagram Figure 2-79 The following figure shows the logic diagram for the intermittent ground fault protection function. Logic diagram of the intermittent ground fault protection - principle Fault Logging A fault event and thus fault logging is initiated when the non-stabilized IN element picks up for the first time. A message IIE Fault det" is produced. The message IIE Fault det" is issued and entered in the fault log (and reported to the system interface) so often until the number of pickups IIE Fault det" has reached the value set for parameter Nos.det.. When this happens, the message Intermitt.EF" is issued and IIE Fault det" is blocked for the fault log and the system interface. This method accounts for the fact that the IN element may also pick up for a normal short-circuit. In this case the pickup does not launch the alarm Intermitt.EF". Intermittent ground faults may cause other time overcurrent elements to pick up (e.g. 50-1, 50N-1, 50Ns-1) and produce a burst of messages. To avoid overflow of the fault log, messages are not entered anymore in the fault log after detection of an intermittent ground fault (message Intermitt.EF") unless they cause a tripping command. If an intermittent ground fault has been detected, the following pickup messages of the time overcurrent protection will still be reported without restraint (see Table 2-13): SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 222 2 Functions Table 2-13 FNo. 1800 223 Unrestricted Messages Message 50-2 picked up" Description 50-2 picked up 2642 67-2 picked up" 67-2 picked up 7551 50-1 InRushPU" 50-1 InRush picked up 7552 50N-1 InRushPU" 50N-1 InRush picked up 7553 51 InRushPU" 51 InRush picked up 7554 51N InRushPU" 51N InRush picked up 7559 67-1 InRushPU" 67-1 InRush picked up 7560 67N-1 InRushPU" 67N-1 InRush picked up 7561 67-TOC InRushPU" 67-TOC InRush picked up 7562 67N-TOCInRushPU" 67N-TOC InRush picked up 7565 Ia InRush PU" Phase A InRush picked up 7566 Ib InRush PU" Phase B InRush picked up 7567 Ic InRush PU" Phase C InRush picked up 7564 Gnd InRush PU" Ground InRush picked up SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.13 Intermittent Ground Fault Protection Table 2-14 shows all messages subject to a restraint mechanism avoiding a message burst during an intermittent ground fault: Table 2-14 FNo. Buffered Messages Message Explanation 1761 50(N)/51(N) PU" 50(N)/51(N) picked up 1762 50/51 Ph A PU" 50/51 Phase A picked up 1763 50/51 Ph B PU" 50/51 Phase B picked up 1764 50/51 Ph C PU" 50/51 Phase C picked up 1810 50-1 picked up" 50-1 picked up 1820 51 picked up" 51 picked up 1765 50N/51NPickedup" 50N/51N picked up 1831 50N-2 picked up" 50N-2 picked up 1834 50N-1 picked up" 50N-1 picked up 1837 51N picked up" 51N picked up 2691 67/67N pickedup" 67/67N picked up 2660 67-1 picked up" 67-1 picked up 2670 67-TOC pickedup" 67-TOC picked up 2692 67 A picked up" 67/67-TOC Phase A picked up 2693 67 B picked up" 67/67-TOC Phase B picked up 2694 67 C picked up" 67/67-TOC Phase C picked up 2646 67N-2 picked up" 67N-2 picked up 2681 67N-1 picked up" 67N-1 picked up 2684 67N-TOCPickedup" 67N-TOC picked up 2695 67N picked up" 67N/67N--TOC picked up 5159 46-2 picked up" 46-2 picked up 5165 46-1 picked up" 46-1 picked up 5166 46-TOC pickedup" 46-TOC picked up 1215 64 Pickup" 64 displacement voltage pick up 1221 50Ns-2 Pickup" 50Ns-2 picked up 1224 50Ns-1 Pickup" 50Ns-1 picked up 1227 51Ns Pickup" 51Ns picked up 6823 START-SUP pu" Startup supervision Pickup Before they are entered in the fault log (event buffer) and transmitted to the system interface or CFC, the messages of table 2-14 are buffered (starting with the first pickup message received after Intermitt.EF" was signalled). The buffering does not apply for signalling to relays and LEDs as it is required by time-graded protection systems for reverse interlocking. The intermediate buffer can store a maximum of two status changes (the most recent ones) for each message. Buffered messages are signalled to the fault log, CFC and to the system interface with the original time flag only when a TRIP command is initiated by a protective function other than the intermittent ground fault protection. This ascertains that a pickup, although delayed, is always signalled in association with each TRIP command. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 224 2 Functions All pickup messages which usually do not occur during an intermittent ground fault are not affected by this mechanism. Among others this includes the pickup and TRIP commands of the following protective functions: * Breaker failure protection, * Overload protection, * Frequency protection and * Voltage protection. The pickup signals of these functions will still be logged immediately. A TRIP command of one of these protective functions will cause the buffered messages to be cleared since no connection exists between tripping function and buffered message. A fault event is cleared when the time T-reset has expired or the TRIP command IEF Trip" has been terminated. Terminating a fault event for the intermittent ground fault protection thus is a special case. It is the time T-reset that keeps the fault event opened and not the pickup. 225 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.13 Intermittent Ground Fault Protection 2.13.2 Setting Notes General The protection function for intermittent ground faults can only take effect and is only accessible if the current to be evaluated (133, INTERM.EF or with Ignd) was configured in address with 3I0 with Ignd,sens.. If not required, this function is set to Disabled. The function can be turned ON or OFF under address 3301 INTERM.EF. The pickup threshold (r.m.s. value) is set in address 3302 Iie>. A rather sensitive setting is possible to respond also to short ground faults since the pickup time shortens as the current in excess of the setting increases. The setting range depends on the selection of the current to be evaluated at address 133 INTERM.EF. The pickup time can be prolonged at address 3303 T-det.ext.. This pickup stabilization is especially important for the coordination with existing analog or electromechanical overcurrent relays. The time T-det.ext. can also be disabled (Tdet.ext. = 0). The stabilized pickup starts the counter T-sum det.. This counter is stopped but not reset when the picked up function drops out. Based on the last counter content the counter resumes counting when the stabilized function picks up next. This sum of individual pickup times, which are to initiate tripping, is set at address 3304 T-sum det.. It represents one of the four selectivity criteria (pickup value Iie>, detection extension time T-det.ext., counter T-sum det. and reset time T-reset) for coordinating the relays on adjacent feeders and is comparable to the time grading of the time overcurrent protection. The relay in the radial network which is closest to the intermittent fault and picks up, will have the shortest summation time T-sum det.. The reset time, after which the summation is reset in healthy operation and the protection resumes normal status, is configured to T-reset at address 3305. Figure 2-80 Example of selectivity criteria of the intermittent ground fault protection Address 3306 Nos.det. specifies the number of pickups after which a ground fault is considered intermittent. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 226 2 Functions 2.13.3 Settings The table indicates region-specific default settings. Column C (configuration) indicates the corresponding secondary nominal current of the current transformer. Addr. Parameter 3301 INTERM.EF 3302 Iie> 3302 Iie> C Setting Options Default Setting Comments OFF ON OFF Intermittent earth fault protection 1A 0.05 .. 35.00 A 1.00 A 5A 0.25 .. 175.00 A 5.00 A Pick-up value of interm. E/F stage 1A 0.05 .. 35.00 A 1.00 A 5A 0.25 .. 175.00 A 5.00 A Pick-up value of interm. E/F stage 3302 Iie> 0.005 .. 1.500 A 1.000 A Pick-up value of interm. E/F stage 3303 T-det.ext. 0.00 .. 10.00 sec 0.10 sec Detection extension time 3304 T-sum det. 0.00 .. 100.00 sec 20.00 sec Sum of detection times 3305 T-reset 1 .. 600 sec 300 sec Reset time 3306 Nos.det. 2 .. 10 3 No. of det. for start of int. E/F prot 2.13.4 Information List No. Information Type of Information Comments 6903 >IEF block SP >block interm. E/F prot. 6921 IEF OFF OUT Interm. E/F prot. is switched off 6922 IEF blocked OUT Interm. E/F prot. is blocked 6923 IEF enabled OUT Interm. E/F prot. is active 6924 IIE Fault det OUT Interm. E/F detection stage Iie> 6925 IIE stab.Flt OUT Interm. E/F stab detection 6926 IIE Flt.det FE OUT Interm.E/F det.stage Iie> f.Flt. ev.Prot 6927 Intermitt.EF OUT Interm. E/F detected 6928 IEF Tsum exp. OUT Counter of det. times elapsed 6929 IEF Tres run. OUT Interm. E/F: reset time running 6930 IEF Trip OUT Interm. E/F: trip 6931 Iie/In= VI Max RMS current value of fault = 6932 Nos.IIE= VI No. of detections by stage Iie>= 227 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.14 Automatic Reclosing System 79 2.14 Automatic Reclosing System 79 From experience, about 85 % of insulation faults associated with overhead lines are arc short circuits which are temporary in nature and disappear when protection takes effect. This means that the line can be connected again. The reconnection is accomplished after a dead time via the automatic reclosing system. If the fault still exists after automatic reclosure (arc has not disappeared, there is a metallic fault), then the protective elements will re-trip the circuit breaker. In some systems several reclosing attempts are performed. Applications * The automatic reclosure system integrated in the 7SJ62/63/64 can also be controlled by an external protection device (e.g. backup protection). For this application, an output contact from the tripping relay must be wired to a binary input of the 7SJ62/63/64 relay. * It is also possible to allow the relay 7SJ62/63/64 to work in conjunction with an external reclosing device. * The automatic reclosure system can also operate in interaction with the integrated synchronizing function (only 7SJ64) or with an external synchrocheck. * Since the automatic reclosing function is not applied when the 7SJ62/63/64 is used to protect generators, motors, transformers, cables and reactors etc., it should be disabled for this application. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 228 2 Functions 2.14.1 Program Execution The 7SJ62/63/64 is equipped with three-pole, single-shot and multi-shot automatic reclosure (AR). Figure 2-81 shows an example of a timing diagram for a successful second reclosure. Figure 2-81 Timing diagram showing two reclosing shots, first cycle unsuccessful, second cycle successful The following figure shows an example of a timing diagram showing for two unsuccessful reclosing shots, with no additional reclosing of the circuit breaker. The number of reclose commands initiated by the automatic reclosure function are counted. A statistical counter is available for this purpose for the first and all subsequent reclosing commands. 229 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.14 Automatic Reclosing System 79 Figure 2-82 Initiation Timing diagram showing two unsuccessful reclosing shots Initiation of the automatic reclosing function can be caused by internal protective functions or externally using a binary input. The automatic reclosing system can be programmed such that any of the elements of Table 2-15 can initiate (Starts 79), not initiate (No influence), or block reclosing (Stops 79): Table 2-15 79 start Non-directional Start Directional Start Start Other 50-1 67-1 SENS. GROUND FLT (50Ns, 51Ns) 50N-1 67N-1 46 50-2 67-2 BINARY INPUT 50N-2 67N-2 51 67-TOC 51N 67N-TOC With the initiation the automatic reclosure function is informed that a trip command is output and the appropriate reclosing program is executed. The binary input messages 2715 >Start 79 Gnd" and 2716 >Start 79 Ph" for starting an automatic reclosure program can also be activated via CFC (fast PLC task processing). Automatic reclosure can thus be initiated via any messages (e.g. protective pickup) if address 7164 BINARY INPUT is set to Starts 79. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 230 2 Functions Action Time The action time serves for monitoring the time between a device pickup and the trip command of a protective function configured as starter. The action time is launched when pickup of any function is detected, which is set as source of the automatic reclosure program. Protection functions which are set to Alarm Only or which in principle should not start a reclosing program do not trigger the action time. If a protective function configured as starter initiates a trip command during the action time, the automatic reclosure program is started. Trip commands of a protective function configured as starter occurring in the time between expiration of the action time and dropout of the device pickup cause the dynamic blocking of the automatic reclosing program. Trip commands of protective functions which are not configured as starter do not affect the action time. If the automatic reclosure program interacts with an external protection device, the device pickup for start of the operating time is communicated to the automatic reclosing program via binary input 2711 >79 Start". Delay of Dead Time Start The initiation of the dead time can be delayed after a 79 start of the binary input message 2754 >79 DT St.Delay". The dead time is not initiated as long as the binary input is active. The initiation takes place only with dropout of the binary input. The delay of the dead time start can be monitored at parameter 7118 T DEAD DELAY. If the time elapses and the binary input is still active, the Automatic Reclosing System 79 changes to the status of the dynamic blocking via (2785 79 DynBlock"). The maximal time delay of the dead time start is logged by the annunciation 2753 79 DT delay ex.". Reclosing Programs Depending on the type of fault, two different reclosing programs can be used. The following applies: * The single phase fault (ground fault) reclosing program applies when all fault protection functions, which initiate automatic reclosure, detected a phase-to-ground fault. The following conditions must apply: only one phase, only one phase and ground or only ground have picked up. This program can be started via a binary input as well. * The multiple phase fault (phase fault program) reclosing program applies to all other cases. That is, when elements associated with two or more phases pickup, with or without the pickup of ground elements, the phase reclosing program is executed. In addition, when automatic reclosing is initiated by other functions, such as negative sequence elements, this program is started. This program can be started via a binary input as well. The reclosure program evaluates only elements during pick up as elements dropping out may corrupt the result if they drop out at different times when opening the circuit breaker. Therefore, the ground fault reclosure program is executed only when the elements associated with one particular phase pick up until the circuit breaker is opened; all others conditions will initiate the phase fault program. For each of the programs, up to 9 reclosing attempts can be separately programmed. The first four reclosing attempts can be set differently for each of the two reclosing programs. The fifth and following automatic reclosures will correspond to the fourth dead time. 231 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.14 Automatic Reclosing System 79 Reclosing Before Selectivity For the automatic reclosure sequence to be successful, faults on any part of the line must be cleared from the feeding line end(s) within the same - shortest possible - time. Usually, therefore, an instantaneous protection element is set to operate before an automatic reclosure. Fast fault termination thus has priority over selectivity aspects as the reclosing action aims at maintaining normal system operation. For this purpose all protective functions which can initiate the automatic reclosure function are set such that they may trip instantaneously or with a very small time delay before auto-reclosure. With the final reclosing attempt, i.e. when no automatic reclosure is expected, protection is to trip with delay according to the grading coordination chart of the network, since selectivity has priority. For details see also information at margin heading "Using the Automatic Reclosure Function" which can be found with the setting notes of the time overcurrent protection functions and the functional description of the intermittent ground fault protection. Single-shot Reclosing When a trip signal is programmed to initiate the automatic reclosing system, the appropriate automatic reclosing program will be executed. Once the circuit breaker has opened, a dead time interval in accordance with the type of fault is started (see also margin heading "Reclosing Programs"). Once the dead time interval has elapsed, a closing signal is issued to reclose the circuit breaker. A blocking time interval TIME RESTRAINT is started at the same time. Within this restraint time it is checked whether the automatic reclosure was performed successfully. If a new fault occurs before the restraint time elapses, the automatic reclosing system is dynamically blocked causing the final tripping of the circuit breaker. The dead time can be set individually for each of the two reclosing programs. Criteria for opening the circuit breaker may either be the auxiliary contacts of the circuit breaker or the dropout of the general device pickup if auxiliary contacts are not configured. If the fault is cleared (successful reclosing attempt), the blocking time expires and automatic reclosing is reset in anticipation of a future fault. The fault is cleared. If the fault is not cleared (unsuccessful reclosing attempt), then a final tripping signal is initiated by one or more protective elements. Multi-shot Reclosing 7SJ62/63/64 permits up to 9 reclosings. The number can be set differently for the phase fault reclosing program and the ground fault reclosing program. The first reclose cycle is, in principle, the same as the single-shot auto-reclosing. If the first reclosing attempt is unsuccessful, this does not result in a final trip, but in a reset of the restraint time interval and start of the next reclose cycle with the next dead time. This can be repeated until the set number of reclosing attempts for the corresponding reclose program has been reached. The dead time intervals for the first four reclosing attempts can be set differently for each of the two reclosing programs. The dead time intervals from the fifth cycle on will be equal to that of the fourth cycle. If one of the reclosing attempts is successful, i.e. the fault disappeared after reclosure, the restraint time expires and the automatic reclosing system is reset. The fault is terminated. If none of the reclosing attempts is successful, then a final circuit breaker trip (according to the grading coordination chart) will take place after the last allowable reclosing attempt has been performed by the protection function. All reclosing attempts were unsuccessful SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 232 2 Functions After the final circuit breaker trip, the automatic reclosing system is dynamically blocked (see below). Restraint Time The function of the restraint time has already been described in the paragraphs at side title "Single-/Multi-Shot Reclosing". The restraint time can be prolonged when the following conditions are fulfilled. The time 211 TMax CLOSE CMD defines the maximum time during which a close command can apply. If a new trip command occurs before this time has run out, the close command will be aborted. If the time TMax CLOSE CMD is set longer than the restraint time TIME RESTRAINT, the restraint time will be extended to the remaining close command duration after expiry! A pickup from a protective function that is set to initiate the automatic reclosing system will also lead to an extension of the restraint time should it occur during this time! 2.14.2 Blocking Static Blocking Static blocking means that the automatic reclosing system is not ready to initiate reclosing, and cannot initiate reclosing as long as the blocking signal is present. A corresponding message 79 is NOT ready" (FNo. 2784) is generated. The static blocking signal is also used internally to block the protection elements that are only supposed to work when reclosing is enabled (see also side title "Reclosing Before Selectivity" further above). The automatic reclosing system is statically blocked if: * The signal >BLOCK 79" FNo.2703) is present at a binary input, as long as the automatic reclosing system is not initiated (associated message: >BLOCK 79"), * The signal >CB Ready" (FNo. 2730) indicates that the circuit breaker disappears via the binary input, if the automatic reclosing system is not initiated (associated message: >CB Ready"), * The number of allowable reclosing attempts set for both reclosing programs is zero (associated message: 79 no cycle"), * No protective functions (parameters 7150 to 7163) or binary inputs are set to initiate the automatic reclosing system (associated message: 79 no starter"), * The circuit breaker position is reported as being "open" and no trip command applies (associated message: 79 BLK: CB open"). This presumes that 7SJ62/63/64 is informed of the circuit breaker position via the auxiliary contacts of the circuit breaker. Dynamic Blocking 233 Dynamic blocking of the automatic reclosure program occurs in those cases where the reclosure program is active and one of the conditions for blocking is fulfilled. The dynamic blocking is signalled by the message 79 DynBlock". The dynamic blocking is associated to the configurable blocking time SAFETY 79 ready. This blocking time is usually started by a blocking condition that has been fulfilled. After the blocking time has elapsed the device checks whether or not the blocking condition can be reset. If the blocking condition is still present or if a new blocking condition is fulfilled, the blocking time is restarted. If, however, the blocking condition no longer holds after the blocking time has elapsed, the dynamic blocking will be reset. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.14 Automatic Reclosing System 79 Dynamic blocking is initiated if: * The maximum number of reclosure attempts has been achieved. If a trip command now occurs within the dynamic blocking time, the automatic reclosure program will be blocked dynamically, (indicated by 79 Max. No. Cyc"). * The protection function has detected a three-phase fault and the device is programmed not to reclose after three-phase faults, (indicated by 79 BLK:3ph p.u."). * When the maximal waiting time T DEAD DELAY for the delay of the dead time initiation by binary inputs runs off without that the binary input >79 DT St.Delay" during this time frame has become inactive. * The action time has elapsed without a TRIP command being issued. Each TRIP command that occurs after the action time has expired and before the picked-up element drops out, will initiate the dynamic blocking (indicated by 79 Tact expired"). * A protective function trips which is to block the automatic reclosure function (as configured). This applies irrespective of the status of the automatic reclosure system (started / not started) if a TRIP command of a blocking element occurs (indicated by 79 BLK by trip"). * The circuit breaker failure function is initiated. * The circuit breaker does not trip within the configured time T-Start MONITOR after a trip command was issued, thus leading to the assumption that the circuit breaker has failed. (The breaker failure monitoring is primarily intended for commissionnig purposes. Commissionnig safety checks are often conducted with the circuit breaker disconnected. The breaker failure monitoring prevents unexpected reclosing after the circuit breaker has been reconnected, indicated by 79 TStart Exp"). * The circuit breaker is not ready after the breaker monitoring time has elapsed, provided that the circuit breaker check has been activated (address 7113 CHECK CB? = Chk each cycle, indicated by 79 T-CBreadyExp"). * The circuit breaker is not ready after maximum extension of the dead time Max. DEAD EXT.. The monitoring of the circuit breaker status and the synchrocheck may cause undesired extension of the dead time. To prevent the automatic reclosure system from assuming an undefined state, the extension of the dead time is monitored. The extension time is started when the regular dead time has elapsed. When it has elapsed, the automatic reclosure function is blocked dynamically and the lockout time launched. The automatic reclosure system resumes normal state when the lock-out time has elapsed and new blocking conditions do not apply (indicated by 79 TdeadMax Exp") . * Manual closing has been detected (externally) and parameter BLOCK MC Dur. (T = 0) was set such that the automatic reclosing system responds to manual closing, * Via a correspondingly masked binary input (FNo. 2703 >BLOCK 79"). If the blocking takes places while the automatic recloser is in normal state, the latter will be blocked statically (79 is NOT ready"). The blocking is terminated immediately when the binary input has been cleared and the automatic reclosure function resumes normal state. If the automatic reclosure function is already running when the blocking arrives, the dynamic blocking takes effect (79 DynBlock"). In this case the activation of the binary input starts the dynamic blocking time SAFETY 79 ready. Upon its expiration the device checks if the binary input is still activated. If this is the case, the automatic reclosure program changes from dynamic blocking to static blocking. If the binary input is no longer active when the time has elapsed and if no new blocking conditions apply, the automatic reclosure system resumes normal state. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 234 2 Functions 2.14.3 Status Recognition and Monitoring of the Circuit Breaker Circuit Breaker Status The detection of the actual circuit breaker position is necessary for the correct functionality of the auto reclose function. The breaker position is detected by the circuit breaker auxiliary contacts and is communicated to the device via binary inputs 4602 >52-b" and 4601 >52-a". Here the following applies: * If binary input 4601 >52-a" and binary input 4602 >52-b" are used, the automatic reclosure function can detect whether the circuit breaker is open, closed or in intermediate position. If both auxiliary contacts detect that the circuit breaker is open, the dead time is started. If the circuit breaker is open or in intermediate position without a trip command being present, the automatic reclosure function is blocked dynamically if it is already running. If the automatic reclosure system is in normal state, it will be blocked statically. When checking whether a trip command applies, all trip commands of the device are taken into account irrespective of whether the function acts as starting or blocking element on behalf of the automatic reclosure program. * If binary input 4601 >52-a" alone is allocated, the circuit breaker is considered open while the binary input is not active. If the binary input becomes inactive while no trip command of (any) function applies, the automatic reclosure system will be blocked. The blocking will be of static nature if the automatic reclosure system is in normal state at this time. If the automatic reclosing system is already running, the blocking will be a dynamic one. The dead time is started if the binary input becomes inactive following the trip command of a starting element 4601 >52-a" = inactive). An intermediate position of the circuit breaker cannot be detected for this type of allocation. * If binary input 4602 >52-b" alone is allocated, the circuit breaker is considered open while the binary input is active. If the binary input becomes active while no trip command of (any) function applies, the automatic reclosure system will be blocked dynamically provided it is already running. Otherwise the blocking will be a static one. The dead time is started if the binary input becomes active following the trip command of a starting element. An intermediate position of the circuit breaker cannot be detected for this type of allocation. * If neither binary input 4602 >52-b" nor 4601 >52-a" are allocated, the automatic reclosure program cannot detect the position of the circuit breaker. In this case, the automatic reclosure system will be controlled exclusively via pickups and trip commands. Monitoring for "52-b without TRIP" and starting the dead time in dependence of the circuit breaker feedback is not possible in this case. 235 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.14 Automatic Reclosing System 79 Circuit Breaker Monitoring The time needed by the circuit breaker to perform a complete reclose cycle can be monitored by the 7SJ62/63/64. Breaker failure is detected: A precondition for a reclosing attempt, following a trip command initiated by a protective relay element and subsequent initiation of the automatic reclosing function, is that the circuit breaker is ready for at least one TRIP-CLOSE-TRIP cycle. The readiness of the circuit breaker is monitored by the device using a binary input >CB Ready". In the case where this signal from the breaker is not available, the circuit breaker monitoring feature should be disabled, otherwise reclosing attempts will remain blocked. * Especially when multiple reclosing attempts are programmed, it is a good idea to monitor the circuit breaker condition not only prior to the first but also to each reclosing attempt. A reclosing attempt will be blocked until the binary input indicates that the circuit breaker is ready to complete another CLOSE-TRIP cycle. * The time needed by the circuit-breaker to regain the ready state can be monitored by the 7SJ62/63/64. The monitoring time CB TIME OUT expires for as long as the circuit breaker does not indicate that it is ready via binary input >CB Ready" (FNo. 2730). Meaning that as the binary input >CB Ready" is cleared, the monitoring time CB TIME OUT is started. If the binary input returns before the monitoring time has elapsed, the monitoring time will be cancelled and the reclosure process is continued. If the monitoring time runs longer than the dead time, the dead time will be extended accordingly. If the monitoring time elapses before the circuit breaker signals its readiness, the automatic reclosure function will be blocked dynamically. Interaction with the synchronism check may cause the dead time to extend inadmissibly. To prevent the automatic reclosure function from remaining in an undefined state, dead time extension is monitored. The maximum extension of the dead time can be set at Max. DEAD EXT.. The monitoring time Max. DEAD EXT. is started when the regular dead time has elapsed. If the synchronism check responds before the time has elapsed, the monitoring time will be stopped and the close command generated. If the time expires before the synchronism check reacts, the automatic reclosure function will be blocked dynamically. Please make sure that the above mentioned time is not shorter than the monitoring time CB TIME OUT. The time 7114 T-Start MONITOR serves for monitoring the response of the automatic reclosure function to a breaker failure. It is activated by a trip command arriving before or during a reclosing operation and marks the time that passes between tripping and opening of the circuit breaker. If the time elapses, the device assumes a breaker failure and the automatic reclosure function is blocked dynamically. If parameter T-Start MONITOR is set to , the start monitoring is disabled. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 236 2 Functions 2.14.4 Controlling Protective Elements Depending on the reclosing cycle it is possible to control elements of the directional and non-directional overcurrent protection by means of the automatic reclosure system (Protective Elements Control). There are three mechanisms: 1. Time overcurrent elements may trip instantaneously depending on the automatic reclosure cycle (T = 0), they may remain unaffected by the auto reclosing function AR (T = T) or may be blocked (T = ). For further information see side title "Cyclic Control". 2. The automatic reclosure states "79M Auto Reclosing ready" and "79M Auto Reclosing not ready" can activate or deactivate the dynamic cold load pick-up function. This function is designed to influence time overcurrent elements (see also Section 2.14.6 and Section 2.4) regarding thresholds and trip time delays. 3. The time overcurrent address 1x14A 50(N)-2 ACTIVE defines whether the 50(N)2 elements are to operate always or only with "79M Auto Reclosing ready" (see Section 2.2). Cyclic Control Control of the overcurrent protection elements takes effect by releasing the cycle marked by the corresponding parameter. The cycle zone release is indicated by the messages 79 1.CycZoneRel" to 79 4.CycZoneRel". If the automatic reclosure system is in normal state, the settings for the starting cycle apply. These settings always take effect when the automatic reclosure system assumes normal state. The settings are released for each following cycle when issuing the close command and starting the blocking time. Following a successful auto reclosing operation (restraint time elapsed) or when reset after blocking, the automatic reclosure system assumes normal state. Control of the protection is again assumed by the parameters for the starting cycle. 237 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.14 Automatic Reclosing System 79 The following figure illustrates the control of the protective stages 50-2 and 50N-2. Figure 2-83 Example Control of protection elements for two-fold, successful auto-reclosure Before the first reclosure faults are to be eliminated quickly applying stages 50-2 or 50N-2. Fast fault termination thus has priority over selectivity aspects as the reclosing action aims at maintaining normal system operation. If the fault prevails, a second tripping is to take place instantaneously and subsequently, a second reclosure. After the second reclosure, however, elements 50-2 or 50N-2 are to be blocked so the fault can be eliminated applying elements 50-1 or 50N-1 according to the networks time grading schedule giving priority to selectivity concerns. Addresses 7202 bef.1.Cy:50-2, 7214 bef.2.Cy:50-2 and 7203 bef.1.Cy:50N-2 and 7215 bef.2.Cy:50N-2 are set to instant. T=0 to enable the stages after the first reclosure. Addresses 7226 bef.3.Cy:50-2 and 7227 bef.3.Cy:50N-2, however, are set to blocked T= to ensure that elements 50-2 and 50N-2 are blocked when the second reclosure applies. The back-up stages e.g., SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 238 2 Functions 50-1 and 50N-1 must obviously not be blocked (addresses 7200, 7201, 7212, 7213, 7224 and 7225). The blocking applies only after reclosure according to the settings address. Hence, it is possible to specify again other conditions for a third reclosure. The blocking conditions are also valid for the zone sequence coordination, provided it is available and activated (address 7140, see also margin heading "Zone Sequencing"). 2.14.5 Zone Sequencing (not available for models 7SJ6***-**A**-) It is the task of the zone sequence coordination to harmonize the automatic reclosure function of this device with that of another device that is part of the same power system. It is a complementary function to the automatic reclosure program and allows for example to perform group reclosing operations in radial systems. In case of multiple reclosures, groups may also be in nested arrangement and further high-voltage fuses can be overgraded or undergraded. Zone sequencing works by blocking certain protective functions depending on the reclose cycle. This is implemented by the protective stages control (see margin heading "Controlling Protective Stages"). As a special feature, changing from one reclosing cycle to the next is possible without trip command only via pickup/dropout of the 50-1 or 50N-1element. The following figure shows an example of a group reclosure at feeder 3. Assume that reclosure is performed twice. For fault F1 at Tap Line #5, protection relays protecting the bus supply and Feeder #3 pickup. The time delay of the 50-2 element protecting Feeder #3 is set so that the Feeder #3 circuit breaker will clear the fault before the fuse at Tap Line #5 is damaged. If the fault was cleared, normal service is restored and all functions return to quiescent after restraint time has expired. Thus the fuse has been protected as well. If the fault continues to exist, a second reclosing attempt will follow in the same manner. High speed element 50-2 is now being blocked at relay protecting Feeder #3. If the fault still remains, only element 50-1 continues being active in Feeder #3 which, however, overgrades the fuse with a time delay of 0.4 s. After the fuse operated to clear the fault, the relays nearer to the fault location will drop out. If the fuse fails to clear the fault, then the 50-1 element protecting Feeder #3 will operate as backup protection. The 50-2 element at the busbar relay is set with a delay of 0.4 seconds, since it supposed to trip the 50-2 elements and the fuses as well. For the second reclosure, the 50-2 element also has to be blocked to give preference to the feeder relay (element 50-1 with 0.4 s). For this purpose, the device has to "know" that two reclosing attempts have already been performed. With this device, zone sequence coordination must be switched off: When pickup of 50-1 or 50N-2 drops out, zone sequence coordination provokes that the reclosing attempts are counted as well. If the fault still persists after the second reclosure, the 501 element, which is set for 0.9 seconds, would serve as backup protection. For the busbar fault F2, the 50-2 element at the bus would have cleared the fault in 0.4 seconds. Zone sequence coordination enables the user to set a relative short time period for element 50-2. element 50-2 is only used as backup protection. If zone se- 239 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.14 Automatic Reclosing System 79 quence coordination is not applied, element 50-1 is to be used only with the relative long time period (0.9 s). Figure 2-84 Zone sequencing with a fault occurring at Tap Line 2 and the busbar 2.14.6 Setting Notes General Settings The internal automatic reclosure system will only be effective and accessible if address 171 79 Auto Recl. is set Enabled during configuration. If not required, this function is set to Disabled. The function can be turned ON or OFF under address 7101 FCT 79. If no automatic reclosures are performed on the feeder for which the 7SJ62/63/64 is used (e.g. cables, transformers, motors, etc.), the automatic reclosure function is disabled by configuration. The automatic reclosure function is then completely disabled, i.e. the automatic reclosure function is not processed in the 7SJ62/63/64. No messages exist for this purpose and binary inputs for the automatic reclosure function are ignored. All parameters of block 71 are inaccessible and of no significance. Blocking Duration for Manual-CLOSE Detection Parameter 7103 BLOCK MC Dur. defines the reaction of the automatic reclosure function when a manual closing signal is detected. The parameter can be set to specify how long the auto reclose function will be blocked dynamically in case of an external manual close-command being detected via binary input (356 >Manual Close"). If the setting is 0, the automatic reclosure system will not respond to a manual close-signal. Restraint Time and Dynamic Blocking The blocking time TIME RESTRAINT (address 7105) defines the time that must elapse, after a successful reclosing attempt, before the automatic reclosing function is reset. If a protective function configured for initiation of the auto-reclosure function provokes a new trip before this time elapses, the next reclosing cycle is started in case of multiple reclosures. If no further reclosure is allowed, the last reclosure will be classed as unsuccessful. In general, a few seconds are sufficient. In areas with frequent thunderstorms or storms, a shorter blocking time may be necessary to avoid feeder lockout due to sequential lightning strikes or flashovers. A longer restraint time should be chosen if there is no possibility to monitor the circuit breaker (see below) during multiple reclosing (e.g. because of missing auxiliary contacts and and information on the circuit breaker ready status). In this case, the restraint time should be longer than the time required for the circuit breaker mechanism to be ready. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 240 2 Functions If a dynamic blocking of the automatic reclosing system was initiated, then reclosing functions remain blocked until the cause of the blocking has been cleared. The functional description gives further information on this topic, see marginal heading "Dynamic Blocking". The dynamic blocking is associated with the configurable blocking time SAFETY 79 ready. Dynamic blocking time is usually started by a blocking condition that has picked up. Circuit Breaker Monitoring Reclosing after a fault clearance presupposes that the circuit breaker is ready for at least one TRIP-CLOSE-TRIP cycle at the time when the reclosing function is initiated (i.e. at the beginning of a trip command): The readiness of the circuit breaker is monitored by the device using a binary input >CB Ready" (FNo. 2730). * It is possible to check the status of the circuit breaker before each reclosure or to disable this option (address 7113, CHECK CB?): CHECK CB? = No check, deactivates the circuit breaker check, CHECK CB? = Chk each cycle, to verify the circuit breaker status before each reclosing command. Checking the status of the circuit breaker is usually recommended. Should the breaker not provide such a signal, you can disable the circuit breaker check at address 7113 CHECK CB? (No check), as otherwise auto-reclosure would be impossible. The status monitoring time CB TIME OUT can be configured at address 7115 if the circuit breaker check was enabled at address 7113. This time is set slightly higher than the maximum recovery time of the circuit breaker following reclosure. If the circuit breaker is not ready after the time has expired, reclosing is omitted and dynamic blocking is initiated. Automatic reclosure thus is blocked. Time Max. DEAD EXT. serves for monitoring the dead time extension. The extension can be initiated by the circuit breaker monitoring time CB TIME OUT and the synchronization function. The monitoring time Max. DEAD EXT. is started after the configured dead time has elapsed. This time must not be shorter than CB TIME OUT. When using the monitoring time CB TIME OUT, the time Max. DEAD EXT. should be set to a value CB TIME OUT. If the auto-reclose system is operated with a synchronization function (internal or external), Max. DEAD EXT. assures that the auto-reclose system does not remain in undefined state when the synchronism check fails to check back. If the synchronization is used as synchronism check (for synchronous systems), the monitoring time may be configured quite short, e.g. to some seconds. In this case the synchronizing function merely checks the synchronism of the power systems. If synchronism prevails it switches in instantaneously, otherwise it will not. If the synchronization is used for synchronous/asynchronous networks, the monitoring time must grant sufficient time for determining the time for switching in. This depends on the frequency slip of the two subnetworks. A monitoring time of 100 s should be sufficient to account for most applications for asynchronous networks. Generally, the monitoring time should be longer than the maximum duration of the synchronization process (parameter 6x12). 241 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.14 Automatic Reclosing System 79 The breaker failure monitoring time 7114 T-Start MONITOR determines the time between tripping (closing the trip contact) and opening the circuit breaker (checkback of the CB auxiliary contacts). This time is started each time a tripping operation takes place. When time has elapsed, the device assumes breaker failure and blocks the auto-reclose system dynamically. Action Time The action time monitors the time between interrogation of the device and trip command of a protective function configured as starter while the auto-reclosure system is ready but not yet running. A trip command issued by a protective function configured as starter occurring within the action time will start the automatic reclosing function. If this time differs from the setting value of T-ACTION (address 7117), the automatic reclosing system will be blocked dynamically. The trip time of inverse tripping characteristics is considerably determined by the fault location or fault resistance. The action time prevents reclosing in case of far remote or high-resistance faults with long tripping time. Trip commands of protective functions which are not configured as starter do not affect the action time. Delay of Dead Time Start The dead time start can be delayed by pickup of the binary input message 2754 >79 DT St.Delay". The maximum time for this can be parameterized under 7118 T DEAD DELAY. The binary input message must be deactivated again within this time in order to start the dead time. The exact sequence is described in the functional description at margin heading "Delay of Dead Time Start". Number of Reclosing Attempts The number of reclosing attempts can be set separately for the "phase program" (address 7136 # OF RECL. PH) and "ground program" (address 7135 # OF RECL. GND). The exact definition of the programs is described in the functional description at margin heading "Reclosing Programs". Close Command: Direct or via Control Address 7137 Cmd.via control can be set to either generate directly the close command via the automatic reclosing function (setting Cmd.via control = none) or have the closing initiated by the control function. If the AR is to be intended to close via the control function, the Manual Close command has to be suppressed during an automatic reclose command. The example in Section 2.2.10 of a MANUAL CLOSE for commands via the integrated control function, has to be extended in this case (see Fig. 2-85). It is detected via the annunciations 2878 79 L-N Sequence" and 2879 79 L-L Sequence" that the automatic reclosure has been started and a reclosure will be initiated after the dead time. The annunciations set the flipflop and suspend the manual close signal until the AR has finished the reclosure attempts. The flipflop is reset via the OR-combination of the annunciations 2784 79 is NOT ready", 2785 79 DynBlock" and 2862 79 Successful". ManCl is initiated if a CLOSE command comes from the control function. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 242 2 Functions Figure 2-85 CFC Logic for ManCI with AR via Control The selection list for parameter 7137 is created dynamically depending on the allocated switchgear components. If one of the switchgear components is selected, usually the circuit breaker 52Breaker", reclosure is accomplished via control. In this case, the automatic reclosure function does not create a close command but issues a close request. It is forwarded to the control which then takes over the switching. Thus, the properties defined for the switchgear component such as interlocking and command times apply. Hence, it is possible that the close command will not be carried out due to an applying interlocking condition. If this behavior is not desired, the auto-reclose function can also generate the close command 79 Close" directly which must be allocated to the associated contact. The CFC Chart as in Figure 2-85 is not needed in this case. Connection to Internal Synchrocheck (only 7SJ64) The auto-reclose function can interact with the internal synchronizing function of the 7SJ64 relay. If this is desired as well as the Manual Close functionality, the CFC chart depicted in Figure 2-85 is obligatory since the synchronizing function always works together with the control function. In addition, one of the four synchronization groups must be selected via parameter 7138 Internal SYNC. Thus, synchronization conditions for automatic reclosing are specified. The selected synchronization group defines in that case the switchgear component to be used (usually the circuit breaker 52Breaker"). The switchgear component defined there and the one specified at 7137 Cmd.via control must be identical. Synchronous reclosing via the close command 79 Close" is not possible. If interaction with the internal synchronization is not desired, the CFC Chart, as in Figure 2-85, is not required and the parameter 7138 is set to none. Auto-Reclosing with External Synchrocheck Parameter 7139 External SYNC can be set to determine that the auto-reclose function operates with external synchrocheck. External synchronization is possible if the parameter is set to YES and 7SJ64 is linked to the external synchrocheck via the message 2865 79 Sync.Request" and the binary input >Sync.release". Note: The automatic reclosure function cannot be connected to the internal and external synchrocheck at the same time ! 243 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.14 Automatic Reclosing System 79 Initiation and Blocking of Autoreclosure by Protective Elements (configuration) At addresses 7150 to 7164, reclosing can be initiated or blocked for various types of protective elements. They constitute the interconnection between protective elements and auto-reclose function. Each address designates a protective function together with its ANSI synonym e.g., 50-2 for the high-set element of the non-directional time overcurrent protection (address 7152). The setting options have the following meaning: * Starts 79 The protective element initiates the automatic reclosure via its trip command; No influence the protective element does not start the automatic reclosure, it may however be initiated by other functions; Stops 79 the protective element blocks the automatic reclosure, it cannot be started by other functions; a dynamic blocking is initiated. Dead Times (1st AR) Addresses 7127 and 7128 are used to determine the duration of the dead times of the 1st cycle. The time defined by this parameter is started when the circuit breaker opens (if auxiliary contacts are allocated) or when the pickup drops out following the trip command of a starter. Dead time before first auto-reclosure for reclosing program "Phase" is set in address 7127 DEADTIME 1: PH, for reclosing program "ground" in address 7128 DEADTIME 1: G. The exact definition of the programs is described in the functional description at margin heading "Reclosing Programs". The length of the dead time should relate to the type of application. With longer lines they should be long enough to make sure that the fault arc disappears and that the air surrounding it is deionized and auto-reclosure can successfully take place (usually 0.9 s to 1.5 s). For lines supplied by more than one side, mostly system stability has priority. Since the deenergized line cannot transfer synchronizing energy, only short dead times are allowed. Standard values are 0.3 s to 0.6 s. In radial systems longer dead times are allowed. Cyclic Control of Protective Functions via Automatic Reclosure Addresses 7200 to 7211 allow cyclic control of the various protective functions by the automatic reclosing function. Thus protective elements can be blocked selectively, made to operate instantaneously or according to the configured delay times. The following options are available: The following options are available: * Set value T=T The protective element is delayed as configured i.e., the autoreclose function does not effect this element; instant. T=0 The protective element becomes instantaneous if the auto-reclose function is ready to perform the mentioned cycle; blocked T= The protective element is blocked if the auto-reclose function reaches the cycle defined in the parameter. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 244 2 Functions Dead Times (2nd to 4th AR) If more than one reclosing cycle was set, you can now configure the individual reclosing settings for the 2nd to 4th cycle. The same options are available as for the first cycle. For the 2nd cycle: Address 7129 DEADTIME 2: PH Dead time for the 2nd reclosing attempt "Phase" Address 7130 DEADTIME 2: G Dead time for the 2nd reclosing attempt ground Addresses 7212 to 7223 allow cyclic control of the various protective functions by the 2nd reclosing attempt For the 3rd cycle: Address 7131 DEADTIME 3: PH Address 7132 DEADTIME 3: G Addresses 7224 to 7235 Dead time for the 3rd reclosing attempt "Phase" Dead time for the 3th reclosing attempt ground allow cyclic control of the various protective functions by the 3rd reclosing attempt For the 4th cycle: Address 7133 DEADTIME 4: PH Address 7134 DEADTIME 4: G Addresses 7236 to 7247 Dead time for the 4th reclosing attempt "Phase" Dead time for the 4th reclosing attempt ground allow cyclic control of the various protective functions by the 4th reclosing attempt Fifth to Ninth Reclosing Attempt If more than four cycles are configured, the dead times set for the fourth cycle also apply to the fifth through to ninth cycle. Blocking ThreePhase Faults Regardless of which reclosing program is executed, automatic reclosing can be blocked for trips following three-phase faults (address 7165 3Pol.PICKUP BLK). The pickup of all three phases for a specific overcurrent element is the criterion required. Blocking of Autoreclose via Internal Control The auto-reclose function can be blocked, if control commands are issued via the integrated control function of the device. The information must be routed via CFC (interlocking task-level) using the CMD_Information function block (see the following figure). Figure 2-86 245 Blocking of the automatic reclose function using the internal control function SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.14 Automatic Reclosing System 79 Zone Sequencing Not available for models 7SJ62/63/64**-**A**At address 7140 ZONE SEQ.COORD., the zone sequencing feature can be turned ON or OFF. If multiple reclosures are performed and the zone sequencing function is deactivated, only those reclosing cycles are counted which the device has conducted after a trip command. With the zone sequencing function switched on, an additional sequence counter also counts such auto-reclosures which (in radial systems) are carried out by relays connected on load side. This presupposes that the pickup of the 50-1/50N-1 elements drops out without a trip command being issued by a protective function initiating the auto-reclose function. The parameters at addresses 7200 through 7247 (see paragraph below at "Initiation and Blocking of Reclosing by Protective Functions" and "Controlling Directional/Non-Directional Overcurrent Protection Stages via Cold Load Pickup") can thus be set to determine which protective elements are active or blocked during what dead time cycles (for multiple reclosing attempts carried out by relays on the load side). In the example shown in Figure 2-52 "Zone sequencing with a fault occurring at Tap Line #5 and the busbar" in the functional description, the zone sequencing was applied in the bus relay. Moreover, the 50-2 elements would have to be blocked after the second reclosure, i.e. address 7214 bef.2.Cy:50-2 is to be set to blocked T=. The zone sequencing of the feeder relays is switched off but the 50-2 elements must also be blocked here after the second reclosing attempt. Moreover, it must be ensured that the 50-2 elements start the automatic reclosing function: address 7152 50-2 set to Starts 79. Controlling Directional / Non-Directional Overcurrent Protection Elements via Cold Load Pickup The cold load pickup function provides a further alternative to control the protection via the automatic reclosing system (see also Section 2.4). This function provides the address 1702 Start Condition It determines the starting conditions for the increased setting values of current and time of the cold load pickup that must apply for directional and non-directional overcurrent protection. If address 1702 Start Condition = 79 ready, the directional and non-directional overcurrent protection always employ the increased setting values if the automatic reclosing system is ready. The auto-reclosure function provides the signal 79 ready for controlling the cold load pickup. The signal 79 ready is always active if the auto-reclosing system is available, active, unblocked and ready for another cycle. Control via the cold load pickup function is non-cyclic. Since control via cold load pickup and cyclic control via auto-reclosing system can run simultaneously, the directional and non-directional overcurrent protection must coordinate the input values of the two interfaces. In this context the cyclic auto-reclosing control has the priority and thus overwrites the release of the cold load pickup function. If the protective elements are controlled via the automatic reclosing function, changing the control variables (e.g. by blocking) has no effect on elements that are already running. The elements in question are continued. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 246 2 Functions Note Regarding Settings List for Automatic Reclosure Function The setting options of address 7137 Cmd.via control are generated dynamically according to the current configuration. Address 7138 Internal SYNC is only available for 7SJ64. 2.14.7 Settings Addr. Parameter Setting Options Default Setting Comments 7101 FCT 79 OFF ON OFF 79 Auto-Reclose Function 7103 BLOCK MC Dur. 0.50 .. 320.00 sec; 0 1.00 sec AR blocking duration after manual close 7105 TIME RESTRAINT 0.50 .. 320.00 sec 3.00 sec 79 Auto Reclosing reset time 7108 SAFETY 79 ready 0.01 .. 320.00 sec 0.50 sec Safety Time until 79 is ready 7113 CHECK CB? No check Chk each cycle No check Check circuit breaker before AR? 7114 T-Start MONITOR 0.01 .. 320.00 sec; 0.50 sec AR start-signal monitoring time 7115 CB TIME OUT 0.10 .. 320.00 sec 3.00 sec Circuit Breaker (CB) Supervision Time 7116 Max. DEAD EXT. 0.50 .. 1800.00 sec; 100.00 sec Maximum dead time extension 7117 T-ACTION 0.01 .. 320.00 sec; sec Action time 7118 T DEAD DELAY 0.0 .. 1800.0 sec; 1.0 sec Maximum Time Delay of DeadTime Start 7127 DEADTIME 1: PH 0.01 .. 320.00 sec 0.50 sec Dead Time 1: Phase Fault 7128 DEADTIME 1: G 0.01 .. 320.00 sec 0.50 sec Dead Time 1: Ground Fault 7129 DEADTIME 2: PH 0.01 .. 320.00 sec 0.50 sec Dead Time 2: Phase Fault 7130 DEADTIME 2: G 0.01 .. 320.00 sec 0.50 sec Dead Time 2: Ground Fault 7131 DEADTIME 3: PH 0.01 .. 320.00 sec 0.50 sec Dead Time 3: Phase Fault 7132 DEADTIME 3: G 0.01 .. 320.00 sec 0.50 sec Dead Time 3: Ground Fault 7133 DEADTIME 4: PH 0.01 .. 320.00 sec 0.50 sec Dead Time 4: Phase Fault 7134 DEADTIME 4: G 0.01 .. 320.00 sec 0.50 sec Dead Time 4: Ground Fault 7135 # OF RECL. GND 0 .. 9 1 Number of Reclosing Cycles Ground 7136 # OF RECL. PH 0 .. 9 1 Number of Reclosing Cycles Phase 7137 Cmd.via control (Setting options depend on configuration) None Close command via control device 7138 Internal SYNC (Setting options depend on configuration) None Internal 25 synchronisation 7139 External SYNC YES NO NO External 25 synchronisation 7140 ZONE SEQ.COORD. OFF ON OFF ZSC - Zone sequence coordination 247 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.14 Automatic Reclosing System 79 Addr. Parameter Setting Options Default Setting Comments 7150 50-1 No influence Starts 79 Stops 79 No influence 50-1 7151 50N-1 No influence Starts 79 Stops 79 No influence 50N-1 7152 50-2 No influence Starts 79 Stops 79 No influence 50-2 7153 50N-2 No influence Starts 79 Stops 79 No influence 50N-2 7154 51 No influence Starts 79 Stops 79 No influence 51 7155 51N No influence Starts 79 Stops 79 No influence 51N 7156 67-1 No influence Starts 79 Stops 79 No influence 67-1 7157 67N-1 No influence Starts 79 Stops 79 No influence 67N-1 7158 67-2 No influence Starts 79 Stops 79 No influence 67-2 7159 67N-2 No influence Starts 79 Stops 79 No influence 67N-2 7160 67 TOC No influence Starts 79 Stops 79 No influence 67 TOC 7161 67N TOC No influence Starts 79 Stops 79 No influence 67N TOC 7162 sens Ground Flt No influence Starts 79 Stops 79 No influence (Sensitive) Ground Fault 7163 46 No influence Starts 79 Stops 79 No influence 46 7164 BINARY INPUT No influence Starts 79 Stops 79 No influence Binary Input 7165 3Pol.PICKUP BLK YES NO NO 3 Pole Pickup blocks 79 7200 bef.1.Cy:50-1 Set value T=T instant. T=0 blocked T= Set value T=T before 1. Cycle: 50-1 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 248 2 Functions Addr. Parameter Setting Options Default Setting Comments 7201 bef.1.Cy:50N-1 Set value T=T instant. T=0 blocked T= Set value T=T before 1. Cycle: 50N-1 7202 bef.1.Cy:50-2 Set value T=T instant. T=0 blocked T= Set value T=T before 1. Cycle: 50-2 7203 bef.1.Cy:50N-2 Set value T=T instant. T=0 blocked T= Set value T=T before 1. Cycle: 50N-2 7204 bef.1.Cy:51 Set value T=T instant. T=0 blocked T= Set value T=T before 1. Cycle: 51 7205 bef.1.Cy:51N Set value T=T instant. T=0 blocked T= Set value T=T before 1. Cycle: 51N 7206 bef.1.Cy:67-1 Set value T=T instant. T=0 blocked T= Set value T=T before 1. Cycle: 67-1 7207 bef.1.Cy:67N-1 Set value T=T instant. T=0 blocked T= Set value T=T before 1. Cycle: 67N-1 7208 bef.1.Cy:67-2 Set value T=T instant. T=0 blocked T= Set value T=T before 1. Cycle: 67-2 7209 bef.1.Cy:67N-2 Set value T=T instant. T=0 blocked T= Set value T=T before 1. Cycle: 67N-2 7210 bef.1.Cy:67 TOC Set value T=T instant. T=0 blocked T= Set value T=T before 1. Cycle: 67 TOC 7211 bef.1.Cy:67NTOC Set value T=T instant. T=0 blocked T= Set value T=T before 1. Cycle: 67N TOC 7212 bef.2.Cy:50-1 Set value T=T instant. T=0 blocked T= Set value T=T before 2. Cycle: 50-1 7213 bef.2.Cy:50N-1 Set value T=T instant. T=0 blocked T= Set value T=T before 2. Cycle: 50N-1 7214 bef.2.Cy:50-2 Set value T=T instant. T=0 blocked T= Set value T=T before 2. Cycle: 50-2 7215 bef.2.Cy:50N-2 Set value T=T instant. T=0 blocked T= Set value T=T before 2. Cycle: 50N-2 7216 bef.2.Cy:51 Set value T=T instant. T=0 blocked T= Set value T=T before 2. Cycle: 51 249 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.14 Automatic Reclosing System 79 Addr. Parameter Setting Options Default Setting Comments 7217 bef.2.Cy:51N Set value T=T instant. T=0 blocked T= Set value T=T before 2. Cycle: 51N 7218 bef.2.Cy:67-1 Set value T=T instant. T=0 blocked T= Set value T=T before 2. Cycle: 67-1 7219 bef.2.Cy:67N-1 Set value T=T instant. T=0 blocked T= Set value T=T before 2. Cycle: 67N-1 7220 bef.2.Cy:67-2 Set value T=T instant. T=0 blocked T= Set value T=T before 2. Cycle: 67-2 7221 bef.2.Cy:67N-2 Set value T=T instant. T=0 blocked T= Set value T=T before 2. Cycle: 67N-2 7222 bef.2.Cy:67 TOC Set value T=T instant. T=0 blocked T= Set value T=T before 2. Cycle: 67 TOC 7223 bef.2.Cy:67NTOC Set value T=T instant. T=0 blocked T= Set value T=T before 2. Cycle: 67N TOC 7224 bef.3.Cy:50-1 Set value T=T instant. T=0 blocked T= Set value T=T before 3. Cycle: 50-1 7225 bef.3.Cy:50N-1 Set value T=T instant. T=0 blocked T= Set value T=T before 3. Cycle: 50N-1 7226 bef.3.Cy:50-2 Set value T=T instant. T=0 blocked T= Set value T=T before 3. Cycle: 50-2 7227 bef.3.Cy:50N-2 Set value T=T instant. T=0 blocked T= Set value T=T before 3. Cycle: 50N-2 7228 bef.3.Cy:51 Set value T=T instant. T=0 blocked T= Set value T=T before 3. Cycle: 51 7229 bef.3.Cy:51N Set value T=T instant. T=0 blocked T= Set value T=T before 3. Cycle: 51N 7230 bef.3.Cy:67-1 Set value T=T instant. T=0 blocked T= Set value T=T before 3. Cycle: 67-1 7231 bef.3.Cy:67N-1 Set value T=T instant. T=0 blocked T= Set value T=T before 3. Cycle: 67N-1 7232 bef.3.Cy:67-2 Set value T=T instant. T=0 blocked T= Set value T=T before 3. Cycle: 67-2 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 250 2 Functions Addr. Parameter Setting Options Default Setting Comments 7233 bef.3.Cy:67N-2 Set value T=T instant. T=0 blocked T= Set value T=T before 3. Cycle: 67N-2 7234 bef.3.Cy:67 TOC Set value T=T instant. T=0 blocked T= Set value T=T before 3. Cycle: 67 TOC 7235 bef.3.Cy:67NTOC Set value T=T instant. T=0 blocked T= Set value T=T before 3. Cycle: 67N TOC 7236 bef.4.Cy:50-1 Set value T=T instant. T=0 blocked T= Set value T=T before 4. Cycle: 50-1 7237 bef.4.Cy:50N-1 Set value T=T instant. T=0 blocked T= Set value T=T before 4. Cycle: 50N-1 7238 bef.4.Cy:50-2 Set value T=T instant. T=0 blocked T= Set value T=T before 4. Cycle: 50-2 7239 bef.4.Cy:50N-2 Set value T=T instant. T=0 blocked T= Set value T=T before 4. Cycle: 50N-2 7240 bef.4.Cy:51 Set value T=T instant. T=0 blocked T= Set value T=T before 4. Cycle: 51 7241 bef.4.Cy:51N Set value T=T instant. T=0 blocked T= Set value T=T before 4. Cycle: 51N 7242 bef.4.Cy:67-1 Set value T=T instant. T=0 blocked T= Set value T=T before 4. Cycle: 67-1 7243 bef.4.Cy:67N-1 Set value T=T instant. T=0 blocked T= Set value T=T before 4. Cycle: 67N-1 7244 bef.4.Cy:67-2 Set value T=T instant. T=0 blocked T= Set value T=T before 4. Cycle: 67-2 7245 bef.4.Cy:67N-2 Set value T=T instant. T=0 blocked T= Set value T=T before 4. Cycle: 67N-2 7246 bef.4.Cy:67 TOC Set value T=T instant. T=0 blocked T= Set value T=T before 4. Cycle: 67 TOC 7247 bef.4.Cy:67NTOC Set value T=T instant. T=0 blocked T= Set value T=T before 4. Cycle: 67N TOC 251 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.14 Automatic Reclosing System 79 2.14.8 Information List No. Information Type of Information Comments 127 79 ON/OFF IntSP 79 ON/OFF (via system port) 2701 >79 ON SP >79 ON 2702 >79 OFF SP >79 OFF 2703 >BLOCK 79 SP >BLOCK 79 2711 >79 Start SP >79 External start of internal A/R 2715 >Start 79 Gnd SP >Start 79 Ground program 2716 >Start 79 Ph SP >Start 79 Phase program 2722 >ZSC ON SP >Switch zone sequence coordination ON 2723 >ZSC OFF SP >Switch zone sequence coordination OFF 2730 >CB Ready SP >Circuit breaker READY for reclosing 2731 >Sync.release SP >79: Sync. release from ext. sync.-check 2753 79 DT delay ex. OUT 79: Max. Dead Time Start Delay expired 2754 >79 DT St.Delay SP >79: Dead Time Start Delay 2781 79 OFF OUT 79 Auto recloser is switched OFF 2782 79 ON IntSP 79 Auto recloser is switched ON 2784 79 is NOT ready OUT 79 Auto recloser is NOT ready 2785 79 DynBlock OUT 79 - Auto-reclose is dynamically BLOCKED 2788 79 T-CBreadyExp OUT 79: CB ready monitoring window expired 2801 79 in progress OUT 79 - in progress 2808 79 BLK: CB open OUT 79: CB open with no trip 2809 79 T-Start Exp OUT 79: Start-signal monitoring time expired 2810 79 TdeadMax Exp OUT 79: Maximum dead time expired 2823 79 no starter OUT 79: no starter configured 2824 79 no cycle OUT 79: no cycle configured 2827 79 BLK by trip OUT 79: blocking due to trip 2828 79 BLK:3ph p.u. OUT 79: blocking due to 3-phase pickup 2829 79 Tact expired OUT 79: action time expired before trip 2830 79 Max. No. Cyc OUT 79: max. no. of cycles exceeded 2844 79 1stCyc. run. OUT 79 1st cycle running 2845 79 2ndCyc. run. OUT 79 2nd cycle running 2846 79 3rdCyc. run. OUT 79 3rd cycle running 2847 79 4thCyc. run. OUT 79 4th or higher cycle running 2851 79 Close OUT 79 - Close command 2862 79 Successful OUT 79 - cycle successful 2863 79 Lockout OUT 79 - Lockout 2865 79 Sync.Request OUT 79: Synchro-check request 2878 79 L-N Sequence OUT 79-A/R single phase reclosing sequence 2879 79 L-L Sequence OUT 79-A/R multi-phase reclosing sequence 2883 ZSC active OUT Zone Sequencing is active 2884 ZSC ON OUT Zone sequence coordination switched ON 2885 ZSC OFF OUT Zone sequence coordination switched OFF 2889 79 1.CycZoneRel OUT 79 1st cycle zone extension release 2890 79 2.CycZoneRel OUT 79 2nd cycle zone extension release 2891 79 3.CycZoneRel OUT 79 3rd cycle zone extension release SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 252 2 Functions No. Information Type of Information Comments 2892 79 4.CycZoneRel OUT 79 4th cycle zone extension release 2899 79 CloseRequest OUT 79: Close request to Control Function 253 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.15 Fault Locator 2.15 Fault Locator The measurement of the distance to a fault is a supplement to the protection functions. Applications * Power transmission within the system can be increased when the fault is located and cleared faster. 2.15.1 Description Initiation Fault location is initiated if the directional or non-directional overcurrent relay elements have initiated a trip signal. Once initiated, the fault locator determines the valid measurement loop and measurement window. Sampled value pairs of short-circuit current and short-circuit voltage, are stored in a buffer, and made available for the impedance calculations R (Resistance) and X (Reactance). Measured quantity filtering and the number of impedance calculations are adjusted automatically to the number of stable measured value pairs. Fault location can also be initiated using a binary input. However, it is a prerequisite that pickup of the time overcurrent protection is performed at the same time (directional or non-directional). This feature allows fault location calculations to proceed even if another protective relay cleared the fault. Measurement Process The evaluation of the measured quantities takes place after the fault has been cleared. At least three result pairs of R and X are calculated from the stored and filtered measured quantities in accordance with the line equations. If fewer than three pairs of R and X are calculated, then the fault location feature will generate no information. Average and standard deviations are calculated from the result pairs. After eliminating "questionable results", which are recognized via a large variance from the standard deviation, average values are calculated once again for X. This average is the fault reactance, and is proportional to the fault distance. Note No calculation of the fault locations is carried out if the voltages are connected phasephase! Loop Selection Using the pickup of the overcurrent time elements (directional or non-directional), the valid measurement loops for the calculation of fault reactances are selected. The fault reactances can, of course, only be calculated for phase-to-ground loops if the device is connected to three current transformers connected in a grounded-wye configuration and three voltage transformers connected in a grounded-wye configuration. Table 2-16 shows the assignment of the evaluated loops to the possible pickup scenarios of the protective elements given that the device is supplied from three voltage transformers connected in a grounded-wye configuration. If the voltage transformers are connected in an open delta configuration, then Table 2-17 applies. Of course, no phase-to-ground loops can be measured in this case. In addition, loops are not available for further calculation if one of the two currents in a loop is less than 10% of the other current in that loop, or if any currents in the loop are less than 10% of the nominal device current. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 254 2 Functions Table 2-16 Pickup Possible Loops A B Selection of the loops to be reported for wye-connected voltage transformers Evaluated Loops Comments A-N, A-B, C-A A-N or A-N and least Ph-Ph B-N, A-B, B-C B-N or B-N and least Ph-Ph C C-N, C-A, B-C C-N or C-N and least Ph-Ph If only one phase is picked up, then only the appropriate phase-to-ground loop is displayed. If the reactance(s) of one or both Ph- Ph loops is/are less than the Ph-N reactance, the Ph-Ph loop with the least reactance is also displayed. N A-N, B-N, C-N least Ph-N Only the Ph-N loop with the least reactance is displayed. A, N A-N A-N The appropriate phase-to-ground loop is displayed. B, N B-N B-N C, N C-N C-N A, B A-B A-B B, C B-C B-C A, C C-A C-A A, B, N A-B, A-N, B-N A-B or A-B and A-N and B-N B, C, N B-C, B-N, C-N B-C or B-C and B-N and C-N A, C, N C-A, A-N, C-N C-A or C-A and A-N and C-N A, B, C A-B, B-C, C-A least Ph-Ph loop A, B, C, N A-B, B-C, C-A least Ph-Ph loop Table 2-17 The appropriate Ph-Ph loop is always displayed; if the reactance differential between the Ph-N loops is larger than 15% of the larger Ph-N loop, both Ph-N loops are also displayed. Only the least Ph-Ph loop is displayed Selection of the loops to be reported for phase-phase connection of voltages Pickup Possible Loops Evaluated Loops A A-B, C-A least Ph-Ph B A-B, B-C least Ph-Ph C C-A, B-C least Ph-Ph A, B A-B A-B B, C B-C B-C A, C C-A C-A A, B, C A-B, B-C, C-A least Ph-Ph loop Result The appropriate Ph-Ph loop is displayed. Comments The least Ph-Ph loop is displayed. The appropriate Ph-Ph loop is displayed. The least Ph-Ph loop is displayed. As result of the fault location, the following is output at the device display or obtained using DIGSI 4: * One or more short-circuit loops from which the fault reactance was derived, * One or more reactances per phase in secondary, * The fault distances, proportional to the reactances, in km or miles of line, converted on the basis of the set line reactance (entered at address 1105 or 1106, see Section 2.1.6.2). Note: The distance result, in miles or kilometers, can only be accurate for homogenous feeder sections. If the feeder is made up of several sections with different reactances, e.g. overhead line - cable sections, then the reactance derived by the fault location can be evaluated with a separate calculation to obtain the fault distance. For transformers, reactors, electrical machines, only the reactance result, not the distance result, is significant. 255 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.15 Fault Locator 2.15.2 Setting Notes General The calculation of fault distance will only take place if address 180 is set to Fault Locator = Enabled. If the fuction is not required Disabled is set. Initiation of Measurement Normally the fault location calculation is started when a protective element initiates a trip signal (address 8001 START = TRIP). However, it may also be initiated when pickup drops out (address 8001 START = Pickup), e.g. when another protective element clears the fault. Irrespective of this fact, calculation of the fault location can be triggered from external via binary input (FNo. 1106 >Start Flt. Loc"). Line Constants To calculate the fault distance in miles or kilometers, the device needs the per distance reactance of the line in /mile or /kilometer. These values were entered during setting of the general protection data (Power System Data 2) under address 1105 or 1106 (see Section 2.1.6.2). 2.15.3 Settings Addr. 8001 Parameter START Setting Options Pickup TRIP Default Setting Pickup Comments Start fault locator with 2.15.4 Information List No. Information Type of Information Comments 1106 >Start Flt. Loc SP >Start Fault Locator 1118 Xsec = VI Flt Locator: secondary REACTANCE 1119 dist = VI Flt Locator: Distance to fault 1123 FL Loop AG OUT Fault Locator Loop AG 1124 FL Loop BG OUT Fault Locator Loop BG 1125 FL Loop CG OUT Fault Locator Loop CG 1126 FL Loop AB OUT Fault Locator Loop AB 1127 FL Loop BC OUT Fault Locator Loop BC 1128 FL Loop CA OUT Fault Locator Loop CA 1132 Flt.Loc.invalid OUT Fault location invalid SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 256 2 Functions 2.16 Breaker Failure Protection 50BF The breaker failure protection function monitors the reaction of a circuit breaker to a trip signal. 2.16.1 Description General If after a programmable time delay, the circuit breaker has not opened, breaker failure protection issues a trip signal via a superordinate circuit breaker (see Figure 2-87, as an example). Figure 2-87 Initiation Functional principle of the breaker failure protection function The breaker failure protection function can be initiated by two different sources: * Trip signals of internal protective functions of the 7SJ62/63/64, * External trip signals via binary inputs (>50BF ext SRC"). For each of the two sources, a unique pickup message is generated, a unique time delay is initiated, and a unique trip signal is generated. The setting values of current threshold and delay time apply to both sources. Criteria There are two criteria for breaker failure detection: * Checking whether the actual current flow effectively disappeared after a tripping command had been issued, * Evaluate the circuit breaker auxiliary contact status. The criteria used to determine if the circuit breaker has operated is selectable and should depend on the protective function that initiated the breaker failure function. When tripping without fault current, e.g. by voltage protection, the current is not a reliable indication as to whether the circuit breaker operated properly. In this case, the position of the breaker auxiliary contact should be used to determine if the circuit breaker properly operated. However, for protective functions that operate in response to currents (i.e. all fault protection functions) both the current criterion and the criterion 257 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.16 Breaker Failure Protection 50BF derived from the circuit breaker auxiliary contact must be fulfilled. Only in case the information retrieved by means of the auxiliary contact criterion is contradictory and therefore erroneous, the current criterion will be used as unique criterion. The current criterion is met if at least one of the three phase currents exceeds a settable threshold (BkrClosed I MIN) (see Section 2.1.3.2, margin heading "Current Flow Monitoring"). This pickup threshold is also used by other protective functions. Evaluation of the circuit breaker auxiliary contacts depends on the type of contacts, and how they are connected to the binary inputs: * Auxiliary contacts for circuit breaker "open" and "closed" are allocated, * Only the auxiliary contact for circuit breaker "open" is allocated, * Only the auxiliary contact for circuit breaker "closed" is allocated, * No auxiliary contact is allocated. Feedback information of the auxiliary contact(s) of the circuit breaker is evaluated, depending on the allocation of binary inputs and auxiliary contacts. After a trip command has been issued it is the aim to detect -- if possible -- by means of the feedback of the circuit breaker's auxiliary contacts whether the breaker is open or in intermediate position. If valid, this information can be used for a proper initiation of the breaker failure protection function. Logic If breaker failure protection is initiated, an alarm message is generated and a settable delay time is started. If once the time delay has elapsed, criteria for a pick-up are still met, a trip signal is issued to a superordinate circuit breaker. Therefore, the trip signal issued by the circuit breaker failure protection is configured to one of the output relays. The following figure shows the logic diagram for the breaker failure protection function. The entire breaker failure protection function may be turned on or off, or it can be blocked dynamically via binary inputs. If one of the criteria (current value, auxiliary contacts) that caused the breaker failure scheme to pickup is no longer met when time delay elapses, pickup drops out and no trip signal is issued by the breaker failure protection function. To protect against spurious tripping due to excessive contact bounce, a stabilization of the binary inputs for external trip signals takes place. This external signal must be present during the entire period of the delay time, otherwise the timer is reset and no tripping signal is issued. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 258 2 Functions Figure 2-88 Logic diagram for breaker failure protection 2.16.2 Setting Notes General 259 Breaker failure protection is only in effect and accessible if address 170 50BF is set to Enabled during configuration of protective functions. If not required, this function is set to Disabled. The function can be turned ON or OFF under address 7001 FCT 50BF. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.16 Breaker Failure Protection 50BF Criteria Address 7004 Chk BRK CONTACT establishes whether or not a breaker auxiliary contact is used, via a binary input, as criteria for pickup. If this address is set to ON, then current criterion and/or the auxiliary contact criterion apply. This is important if the current is smaller than the configured current threshold (BkrClosed I MIN, address 212) despite of the fact that the circuit breaker is closed. The latter may apply if protective tripping was caused by a voltage measurement (e.g. 64 TRIP, 59-1 TRIP / 59- 2 TRIP, 27-1 TRIP / 27-2 TRIP). If these protective functions issue a trip command, the criteria for current and auxiliary contacts are linked by a logical OR operation. Without the auxiliary contact criterion the circuit breaker failure protection would not be able to take effect in this case. For all other protection functions the current and auxiliary contact criteria are combined by logical AND as long as the address Chk BRK CONTACT is set to ON. The pickup threshold BkrClosed I MIN setting of integrated current supervision (address 212) refers to all three phases. The threshold value must be set at a level below the minimum fault current for which the function must operate. A setting of 10% below the minimum fault current for which breaker failure protection must operate is recommended. The pickup value should not be set too low, otherwise, the danger exists that switching off transients in the current transformer secondary circuit could lead to extended drop out times under conditions of extremely high current to be switched off. In addition, it should be noted that other protection functions depend on the pickup value BkrClosed I MIN as well (e.g. voltage protection, overload protection, and restart inhibit for motors). Time Delay The time delay is entered at address 7005 TRIP-Timer. This setting should be based on the maximum circuit breaker operating time plus the dropout time of the current flow monitoring element plus a safety margin which takes into consideration the tolerance of the time delay. In case of an external start, the set time delay is reduced automatically by 10 ms in order to compensate the residual time of the external start. Figure 2-89 illustrates the time sequences. Figure 2-89 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 Timing for a Typical Breaker Failure Scenario 260 2 Functions 2.16.3 Settings Addr. Parameter Setting Options Default Setting Comments 7001 FCT 50BF OFF ON OFF 50BF Breaker Failure Protection 7004 Chk BRK CONTACT OFF ON OFF Check Breaker contacts 7005 TRIP-Timer 0.06 .. 60.00 sec; 0.25 sec TRIP-Timer 2.16.4 Information List No. Information Type of Information Comments 1403 >BLOCK 50BF SP >BLOCK 50BF 1431 >50BF ext SRC SP >50BF initiated externally 1451 50BF OFF OUT 50BF is switched OFF 1452 50BF BLOCK OUT 50BF is BLOCKED 1453 50BF ACTIVE OUT 50BF is ACTIVE 1456 50BF int Pickup OUT 50BF (internal) PICKUP 1457 50BF ext Pickup OUT 50BF (external) PICKUP 1471 50BF TRIP OUT 50BF TRIP 1480 50BF int TRIP OUT 50BF (internal) TRIP 1481 50BF ext TRIP OUT 50BF (external) TRIP 261 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.17 Flexible Protection Functions (7SJ64 only) 2.17 Flexible Protection Functions (7SJ64 only) The flexible protection function is a general function applicable for a variety of protection principles depending on its parameter settings. The user can create up to 20 flexible protection functions. Each function can be used either as an autonomous protection function, as an additional protective element of an existing protection function or as a universal logic, e.g. for monitoring tasks. 2.17.1 Functional Description General Table 2-18 The function is a combination of a standard protection logic and a characteristic (measured quantity or derived quantity) that is adjustable via parameters. The characteristics listed in table 2-18 and the derived protection functions are available. Possible Protection Functions Characteris- Characteristic / Measured Quantitic Group ty Current Frequency Voltage Power Binary input Protective Function ANSI No. Operating Mode 3-phase 1-phase I RMS value of fundamental - Time overcurrent proteccomponent tion 50, 50G X X Irms True RMS (r.m.s. value) - Time overcurrent protection Overload protection 50, 50G X X 3I0 Zero sequence system - Time overcurrent protection, ground 50N X I1 Positive sequence component I2 Negative sequence compo- - Negative sequence pronent tection 46 f Frequency - Frequency protection 81U/O df/dt Frequency change - Frequency change protec- 81R tion V RMS value of fundamental - Voltage protection component - Displacement voltage 27, 59, 59G X X Vrms True RMS (r.m.s. value) - Voltage protection - Displacement voltage 27, 59, 59G X X 3V0 Zero-sequence system - Displacement voltage 59N X V1 Positive sequence compo- - Voltage protection nent 27, 59 X V2 Negative sequence compo- - Voltage asymmetry nent 47 X P Active power - Reverse power protection 32R, 32, 37 - Power protection Q Reactive power - Power protection 32 X X cos Power factor - Power factor 55 X X - Binary input - External trip commands X X without phase reference X X without phase reference Section 2.18 gives an application example of the function reverse power protection". SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 262 2 Functions The maximum 20 configurable protection functions operate independently of each other. The following description concerns one function; it can be applied accordingly to all other flexible functions. The logic diagram 2-90 illustrates the description. Function Logic The function can be switched ON and OFF or, it can be set to Alarm Only. In this status, a pickup condition will neither initiate fault recording nor start the trip time delay. Tripping is thus not possible. Changing the Power System Data 1 after flexible functions have been configured may cause these functions to be set incorrectly. Message (FNo. 235.2128 $00 inval.set") reports this condition. The function is inactive in this case and function's setting has to be modified. Blocking Functions The function can be blocked via binary input (FNo. 235.2110 >BLOCK $00") or via local operating terminal (Control" -> Tagging" -> Set"). Blocking will reset the function's entire measurement logic as well as all running times and indications. Blocking via the local operating terminal may be useful if the function is in a status of permanent pickup which does not allow the function to be reset. In context with voltage-based characteristics, the function can be blocked if one of the measuring voltages fails. Recognition of this status is either accomplished by the relay's internal Fuse-Failure-Monitor" (FNo. 170 VT FuseFail"; see chapter 2.11.1) or via auxiliary contacts of the voltage transformer CB (FNo. 6509 >FAIL:FEEDER VT" and FNo. 6510 >FAIL: BUS VT"). This blocking mechanism can be enabled or disabled in the according parameters. The associated parameter BLK.by Vol.Loss is only available if the characteristic is based on a voltage measurement. When using the flexible function for power protection or power monitoring, it will be blocked if currents fall below 0.03 INom. Operating Mode, Measured Quantity, Measurement Method The flexible function can be tailored to assume a specific protective function for a concrete application in parameters OPERRAT. MODE, MEAS. QUANTITY, MEAS. METHOD and PICKUP WITH. Parameter OPERRAT. MODE can be set to specify whether the function works 3-phase, 1-phase or no reference, i.e. without a fixed phase reference. The three-phase method evaluates all three phases in parallel. This implies that threshold evaluation, pickup indications and trip time delay are accomplished selectively for each phase and parallel to each other. This may be for example the typical operating principle of a three-phase time overcurrent protection. When operating single-phase, the function employs either a phase's measured quantity, which must be stated explicitly, (e.g. evaluating only the current in phase Ib), the measured ground current In or the measured displacement voltage Vn. If the characteristic relates to the frequency or if external trip commands are used, the operating principle is without (fixed) phase reference. Additional parameters can be set to specify the used MEAS. QUANTITY and the MEAS. METHOD. The MEAS. METHOD determines for current and voltage measured values whether the function uses the rms value of the fundamental component or the normal r.m.s. value (true RMS) that evaluates also harmonics. All other characteristics use always the rms value of the fundamental component. Parameter PICKUP WITH moreover specifies whether the function picks up on exceeding the threshold (>-element) or on falling below the threshold (<-element). Characteristic Curve The function's characteristic curve is always definite time"; this means that the delay time is not affected by the measured quantity. 263 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.17 Flexible Protection Functions (7SJ64 only) Function Logic Figure 2-90 Figure 2-90 shows the logic diagram of a three-phase function. If the function operates on one phase or without phase reference, phase selectivity and phase-specific indications are not relevant. Logic diagram of the flexible protection functions SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 264 2 Functions The parameters can be set to monitor either exceeding or dropping below of the threshold. The configurable pickup delay time will be started once the threshold (>element) has been exceeded. When the delay time has elapsed and the threshold is still violated, the pickup of the phase (e.g. no. 235.2122 $00 pickup A")and of the function (no. 235.2121 $00 picked up") is reported. If the pickup delay is set to zero, the pickup will occur simultaneously with the detection of the threshold violation. If the function is enabled, the pickup will start the trip delay time and the fault log. This is not the case if set to "Alarm only". If the threshold violation persists after the trip delay time has elapsed, the trip will be initiated upon its expiration (no. 235.2126 $00 TRIP"). The timeout is reported via (no. 235.2125 $00 Time Out"). Expiry of the trip delay time can be blocked via binary input (no. 235.2113 >$00 BLK.TDly"). The delay time will not be started as long as the binary input is active; a trip can thus be initiated. The delay time is started after the binary input has dropped out and the pickup is still present. It is also possible to bypass the expiration of the delay time by activating binary input (no. 235.2111 >$00 instant."). The trip will be launched immediately when the pickup is present and the binary input has been activated. The trip command can be blocked via binary inputs (no. 235.2115 >$00 BL.TripA") and (no. 235.2114 >$00 BLK.TRIP"). The phase-selective blocking of the trip command is required for interaction with the inrush restraint (see Interaction with other functions"). The function's dropout ratio can be set. If the threshold (>-element) is undershot after the pickup, the dropout delay time will be started. The pickup is maintained during that time, a started trip delay time continues to count down. If the trip delay time has elapsed while the dropout delay time is still during, the trip command will only be given if the current threshold is exceeded. The element will only drop out when the dropout delay time has elapsed. If the time is set to zero, the dropout will be initiated immediately once the threshold is undershot. External Trip Commands The logic diagram does not explicitly depict the external trip commands since their functionality is analogous. If the binary input is activated for external trip commands (no. 235.2112 >$00 Dir.TRIP"), it will be logically treated as threshold overshooting, i.e. once it has been activated, the pickup delay time is started. If the pickup delay time is set to zero, the pickup condition will be reported immediately starting the trip delay time. Otherwise, the logic is the same as depicted in Figure 2-90. Interaction with Other Functions The flexible protection functions interact with a number of other functions such as the * Breaker failure protection: The breaker failure protection is started automatically if the function initiates a trip. The trip will, however, only take place if the current criterion is met at this time, i.e. the set minimum current threshold 212 BkrClosed I MIN (Power System Data 1) has been exceeded. * Automatic reclosing (AR): The AR cannot be started directly. In order to interact with the AR, the trip command of the flexible function needs be linked in CFC to binary input no. 2716 >Start 79 Ph" or no. 2715.>Start 79 Gnd". Using an operating time requires the pickup of the flexible function to be linked to binary input no. 2711 >79 Start". * Fuse-Failure-Monitor (see description at Blocking Functions"). 265 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.17 Flexible Protection Functions (7SJ64 only) * Inrush restraint: Direct interaction with the inrush restraint is not possible. In order to block a flexible function by the inrush restraint, the blocking must be carried out in CFC. The flexible function provides three binary inputs for blocking trip commands selectively for each phase (no. 235.2115 to 235.2117). They have to be linked with the phase-selective indications for detecting the inrush (no. 1840 to 1842). Activating a crossblock function requires the phase-selective inrush indications to be logically combined with the binary input for blocking the function trip command (no. 235.2114 >$00 BLK.TRIP"). The flexible function also needs to be delayed by at least 20 ms to make sure that the inrush restraint picks up before the flexible function. * Entire relay logic: The pickup signal of the flexible function is added to the general device pickup, the trip signal is added to the general device trip (see also Chapter 2.22). All functions associated with general device pickup and tripping are thus also applied to the flexible function. After the picked up element has dropped out, the trip signals of the flexible protection functions are held up at least for the specified minimum trip command time 210 T TRIPCOM MIN. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 266 2 Functions 2.17.2 Setting Notes The Device Configuration allows the user to specify the number of flexible protection functions to be used (see also chapter 2.1.1). If a flexible function is disabled in the Device Configuration (removing the checkmark), all settings and configurations associated with this function are deleted or reset to their default values. General The General" dialog box in DIGSI offers parameter FLEXIBLE FUNC. which can be set to OFF, ON or Alarm Only. In Alarm Only mode, the function does not open fault logs, initiate Active" indications or trip commands and nor does it influence the breaker failure protection. This operating mode is therefore preferable if a flexible function is not desired to work as protective function. Besides that the OPERRAT. MODE can be configured: 3-phase - The functions evaluate the three-phase measuring system, i.e. all three phases are covered in parallel. A typical example is the three-phase time overcurrent protection. 1-phase - The functions evaluate only the individual measured value. This may be an individual phase value (e.g. VB) or a ground quantity (VN or IN). If set to no reference, the measured values are evaluated irrespective of whether current and voltage are connected in one or three phases. Table 2.17 provides an overview of which characteristics can be operated in which mode. Measured Quantity In the Measured quantity" dialog box, the user can select the measured value the protective function evaluates. This value may be calculated or measured directly. The offered setting options depend on the type of measured value processing in parameter OPERRAT. MODE (see following table). Table 2-19 Parameters "Operating Mode" and "Measured Quantity" Parameter OPERRAT. MODE Parameter MEAS. QUANTITY Setting Measurement Method 267 Setting option 1-phase, 3-phase Current Voltage P forward P reverse Q forward Q reverse Power factor without reference Frequency df/dt rising df/dt falling Binray Input The measurement methods listed in the following tables can be set for the measured quantities of current, voltage and power. They also indicate how the available measurement method, depend on the selected operating mode and the measured quantity. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.17 Flexible Protection Functions (7SJ64 only) Table 2-20 Operating Mode 3-phase Parameters in dialog box "Measurement Method", 3-phase operation Measured Quantity Current, Voltage Notes Parameter MEAS. METHOD Setting Options Fundamental wave Only the fundamental wave is evaluated, harmonics are suppressed. This is the standard measurement method of the protection functions. Attention: The voltage threshold value does not depend on the parameter VOLTAGE SYSTEM and is always configured as phase-to-phase voltage. True RMS The "true" r.m.s value is determined, i.e. harmonics are evaluated. This procedure is used for, example, if a simple overload protection is realized on the basis of a current measurement since harmonics contribute to thermal heating. Attention: The voltage threshold value does not depend on the parameter VOLTAGE SYSTEM and is always configured as phase-to-phase voltage. Positive sequence system, In order to implement certain applications, it is possible to Negative sequence system, enable either the positive or the negative sequence system as Zero-sequence system measurement method. Examples are: - I2 (negative sequence protection) - V2 (voltage asymmetry) If the zero sequence system is selected, additional zerocurrent or zero-voltage functions can be implemented that work independently of the ground quantities IN and VN measured directly via transformers. Attention:The parameterization of the voltage threshold depends on the parameter VOLTAGE SYSTEM: - VOLTAGE SYSTEM = Phase-to-phase:sym. component * 3 - VOLTAGE SYSTEM = Phase-to-ground:sym. component * 3 Voltage Parameter VOLTAGE SYSTEM Setting option Phase-to-phase Phase-to-ground If phase-to-ground voltages are connected to the device (see setting 213 VT Connect. 3ph), the user can select whether a 3phase voltage function should evaluate the phase-to-ground or the phase-to-phase voltages. If phase-to-phase is selected, these values are calculated from the phase-to-ground voltages. This selection is significant, e.g. for single-phase faults. If the faulted voltage breaks down to zero, the affected phase-toground voltage is zero, whereas the affected phase-to-phase voltages collapse to the amount of a phase-to-ground voltage. The parameter is hidden if phase-to-phase voltages are connected. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 268 2 Functions Note The three-phase voltage protection with phase-to-phase quantities (measured or calculated) offers a special behavior for phase-selective pickup messages since the phase-selective pickup message "Flx01 Pickup ABC" is assigned to the corresponding measured value channel "abc". Single-phase faults: If, for example,the voltage VA collapses to such an extent that the voltages VAB and VCA fall below their thresholds, the device will report the messages "Flx01 Pickup A" and "Flx01 Pickup C" since the undershooting was detected on the first and third measured value channel. Two-phase faults: If, for example, voltage VAB collapses to such an extent that it falls below its threshold, the device will report the pickup signal "Flx01 Pickup A" since the undershooting was detected on the first measured value channel. Note In three-phase voltage protection, the configured voltage threshold is always interpreted as phase-to-phase quantity. This applies also if a phase-to-ground system is connected in 213 VT Connect. 3ph (Power System Data 1) and the parameter VOLTAGE SYSTEM of the flexible function also evaluates the phase-to-ground system. 269 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.17 Flexible Protection Functions (7SJ64 only) Table 2-21 Operating Mode 1-phase Parameter in dialog box "Measurement Method", 1-phase operation Measured Quantity Current, Voltage Current Notes Parameter MEAS. METHOD Setting option Fundamental wave Only the fundamental wave is evaluated, harmonics are suppressed. This is the standard measurement method of the protection functions. True RMS The true" r.m.s value is determined, i.e. harmonics are evaluated. This procedure is used for, example, if a simple overload protection is realized on the basis of a current measurement since harmonics contribute to thermal heating. Parameter CURRENT Setting option Ia Ib Ic IN INs Voltage Parameter VOLTAGE Setting option Vab Vbc Vca Vag Vbg Vcg VN P forward, P reverse, Q forward, Q reverse It is determined which current measuring channel will be evaluated by the function. According to device variant, either IN (normally sensitive ground current input) or INs (sensitive ground current input) are available. It is determined which voltage measuring channel will be evaluated by the function. When selecting a phase-to-phase voltage, the threshold must be set as phase-to-phase value; when selecting a phase-to-ground value as phase-to-ground voltage. The scope of the function texts depends on the voltage transformer connection (see address 213 VT Connect. 3ph). Parameter POWER Setting option Ia Vag Ib Vbg Ic Vcg It is determined which power measuring channel (current and voltage) will be evaluated by the function. The parameter is hidden if phase-to-phase voltages are connected (see address 213 VT Connect. 3ph). Note In single-phase voltage protection, the configured voltage threshold is always interpreted as voltage at the terminal. The setting in 213 VT Connect. 3ph (Power System Data 1) is ignored in this case. Forward direction of power quantities (P forward, Q forward) is in direction of the line. The flexible function ignores parameter (1108 P,Q sign) for sign inversion of the power display in the operational measured values. Parameter PICKUP WITH specifies whether the function picks up on undershooting or overshooting of the configured threshold. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 270 2 Functions Settings The pickup thresholds, delay times and dropout ratios of the flexible protection function are set in the DIGSI Settings" dialog box. The function's pickup threshold is set in parameter P.U. THRESHOLD. The TRIP delay time is set in parameter T TRIP DELAY. Both setting values must be selected to suit the required application. The pickup may be delayed via parameter T PICKUP DELAY. This parameter is usually set to zero for protective applications (default) since a protective function is desired to pick up as soon as possible. A setting other than zero may be useful if it is not desired that a fault log is opened each time the pickup threshold is briefly violated. This is the case, for example, with line protection, or if the function is used not for protection but for monitoring purposes. When setting small power thresholds, it must be observed that a power calculation requires at least a current of 0.03 INom. The power calculation is blocked for smaller currents. Dropout of the pickup condition can be delayed in parameter T DROPOUT DELAY. This setting, too, is set to zero by default. A setting other than zero may be useful if the device interacts with electro-mechanical devices whose dropout times are significantly longer than those of the numerical protection device (see also section 2.2). When using the dropout delay time, it is recommended to set it shorter than the TRIP delay time to avoid "race conditions" of the two times. In parameter BLK.by Vol.Loss, the user can specify whether a function, whose measured quantity is based on a voltage measurement (voltage measured quantities, P forward, P reverse, Q forward, Q reverse and power factor), is blocked in the event of a measuring voltage failure (setting Yes) or not (setting No). The function's dropout ratio can be set in parameter DROPOUT RATIO. The standard dropout ratio of protective functions is 0.95 (default). When using the function as power protection, the dropout ratio should be set to at least 0.9. The same applies when using the symmetrical components of current and voltage. If the dropout ratio is reduced, it is recommended to test pickup of the function for any signs of "chattering". Moreover, it is important that no dropout ratio is configured for the measured values of frequency (f) and frequency change (df/dt) since it employs a fixed dropout difference. Renaming Messages, Checking Allocations After setting a flexible function, the following additional steps are necessary: * Open the Configuration Matrix in DIGSI. * Rename the neutral message texts to suit the application. * Check configurations for contacts and in operating and fault buffers or set according to the requirements. Additional Information 271 The following additional note must be observed: * Since the power factor is not capable of distinguishing between capacitive and inductive, the sign of the reactive power may be used as an additional criterion by means of CFC. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.17 Flexible Protection Functions (7SJ64 only) 2.17.3 Settings Addresses which have an appended "A" can only be changed with DIGSI, under "Display Additional Settings". Addr. Parameter Setting Options Default Setting Comments 0 FLEXIBLE FUNC. OFF ON Alarm Only OFF Flexible Function 0 OPERRAT. MODE 3-phase 1-phase no reference 3-phase Mode of Operation 0 MEAS. QUANTITY Please select Current Voltage P forward P reverse Q forward Q reverse Power factor Frequency df/dt rising df/dt falling Binray Input Please select Selection of Measured Quantity 0 MEAS. METHOD Fundamental True RMS Positive seq. Negative seq. Zero sequence Fundamental Selection of Measurement Method 0 PICKUP WITH Exceeding Dropping below Exceeding Pickup with 0 CURRENT Ia Ib Ic In In sensitive Ia Current 0 VOLTAGE Please select Va-n Vb-n Vc-n Va-b Vb-c Vc-a Vn Please select Voltage 0 POWER Ia Va-n Ib Vb-n Ic Vc-n Ia Va-n Power 0 VOLTAGE SYSTEM Phase-Phase Phase-Earth Phase-Phase Voltage System 0 P.U. THRESHOLD 0.05 .. 35.00 A 2.00 A Pickup Threshold 0 P.U. THRESHOLD 0.05 .. 35.00 A 2.00 A Pickup Threshold 0 P.U. THRESHOLD 0.001 .. 1.500 A 0.100 A Pickup Threshold SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 272 2 Functions Addr. Parameter Setting Options Default Setting Comments 0 P.U. THRESHOLD 2.0 .. 260.0 V 110.0 V Pickup Threshold 0 P.U. THRESHOLD 2.0 .. 200.0 V 110.0 V Pickup Threshold 0 P.U. THRESHOLD 45.50 .. 54.50 Hz 51.00 Hz Pickup Threshold 0 P.U. THRESHOLD 55.50 .. 64.50 Hz 61.00 Hz Pickup Threshold 0 P.U. THRESHOLD 0.10 .. 20.00 Hz/s 5.00 Hz/s Pickup Threshold 0 P.U. THRESHOLD 0.5 .. 10000.0 W 200.0 W Pickup Threshold 0 P.U. THRESHOLD -0.99 .. 0.99 0.50 Pickup Threshold 0 T TRIP DELAY 0.00 .. 3600.00 sec 1.00 sec Trip Time Delay 0A T PICKUP DELAY 0.00 .. 60.00 sec 0.00 sec Pickup Time Delay 0A T DROPOUT DELAY 0.00 .. 60.00 sec 0.00 sec Dropout Time Delay 0A BLK.by Vol.Loss NO YES YES Block in case of Meas.-Voltage Loss 0A DROPOUT RATIO 0.70 .. 0.99 0.95 Dropout Ratio 0A DROPOUT RATIO 1.01 .. 3.00 1.05 Dropout Ratio 2.17.4 Information List No. Information Type of Information Comments 235.2110 >BLOCK $00 SP >BLOCK Function $00 235.2111 SP >Function $00 instantaneous TRIP SP >Function $00 Direct TRIP >$00 instant. 235.2112 >$00 Dir.TRIP 235.2113 >$00 BLK.TDly SP >Function $00 BLOCK TRIP Time Delay 235.2114 >$00 BLK.TRIP SP >Function $00 BLOCK TRIP 235.2115 >$00 BL.TripA SP >Function $00 BLOCK TRIP Phase A 235.2116 >$00 BL.TripB SP >Function $00 BLOCK TRIP Phase B 235.2117 >$00 BL.TripC SP >Function $00 BLOCK TRIP Phase C 235.2118 $00 BLOCKED OUT Function $00 is BLOCKED 235.2119 $00 OFF OUT Function $00 is switched OFF 235.2120 $00 ACTIVE OUT Function $00 is ACTIVE 235.2121 $00 picked up OUT Function $00 picked up 235.2122 $00 pickup A OUT Function $00 Pickup Phase A 235.2123 $00 pickup B OUT Function $00 Pickup Phase B 235.2124 $00 pickup C OUT Function $00 Pickup Phase C 235.2125 $00 Time Out OUT Function $00 TRIP Delay Time Out 235.2126 $00 TRIP OUT Function $00 TRIP 235.2128 $00 inval.set OUT Function $00 has invalid settings 236.2127 BLK. Flex. Fct. IntSP BLOCK Flexible Function 273 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.18 Reverse-Power Protection Application with Flexible Protection Function 2.18 Reverse-Power Protection Application with Flexible Protection Function 2.18.1 Description General The flexible protection functions allow a single-element or multi-element directional protection to be implemented. Each directional element can be operated on one or on three phases. The elements can optionally use the active power forward, active power reverse, reactive power forward or reactive power reverse as measuring quantity. The elements can pick up on undershooting or on overshooting of the threshold. Table 222 shows possible applications for directional protection. Table 2-22 Overview of directional protection applications Type of Evaluation Direction P Q Overshooting Undershooting forward - Monitoring of the forward - detection of motors running at power thresholds of equipment no-load (transformers, lines) reverse - protection of a local industrial network against feeding energy back into the utility grid - detection of reverse energy supply from motors forward - monitoring of reactive power thresholds of equipment (transformers, lines) - connecting a capacitor bank for reactive power compensation reverse - monitoring of reactive power thresholds of equipment (transformers, lines) - de-energizing a capacitor bank The following example depicts a typical application where the flexible function acts as reverse-power protection. Disconnecting Facility The example in figure 2-91 shows an industrial substation with autonomous power supply from the illustrated generator. All lines and the busbar have a three-phase layout (with exception of the ground connections and the connection to the voltage measurement at the generator). Feeder 1 and 2 supply the consumers on customer side. Industrial customers usually obtain their power from the utility. The generator runs only in synchronous operation without supplying power. If the utility can no longer maintain the required supply quality, the substation is disconnected from the utility grid and the generator assumes the autonomous supply. In the example, the substation is disconnected from the utility grid when the frequency leaves the nominal range (e.g. 1 to 2% deviation from the nominal frequency), the voltage exceeds or falls under a certain preset value or the generator feeds back active power into the utility grid. Depending on the user's requirements, some of these criteria are linked further. This would be implemented using CFC. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 274 2 Functions The example illustrates how a reverse-power protection is implemented by means of the flexible protection functions. Frequency protection and voltage protection are described in Sections 2.9 and 2.6. Figure 2-91 275 Example of a substation with autonomous generator supply SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.18 Reverse-Power Protection Application with Flexible Protection Function Substation Layout A 110-kV line connects the substation to the utility grid on high-voltage side. Circuitbreaker CB1 belongs to the utility grid. The switch-disconnector separates the substation from the utility grid if necessary. The transformer with a ratio of 10:1 transforms the voltage level to 11 kV. On low-voltage side, transformer, generator and the two feeders are connected on a busbar. The circuit-breakers CB2 to CB5 disconnect consumers and equipment from the busbar. Table 2-23 System data for the application example Power System Data Generator nominal power Protective Functionality SN,Gen = 38.1 MVA Transformer nominal power SN,Transformer = 38.1 MVA Nominal voltage of high-voltage side VNom = 110 kV Nominal voltage of busbar side VNom = 11 kV Nominal primary CT current on busbar side IN,prim = 2000 A Nominal secondary CT current on busbar side IN,sec = 1 A Nominal primary VT voltage on busbar side VN,prim = 11 kV Secondary primary VT voltage on busbar side VN,sec = 100 V The 7SJ64 protective relay will disconnect the substation from the utility grid in case the generator feeds back energy into the utility grid (protective function P rev>). This functionality can be achieved using a flexible protection function. Disconnection will also be initiated if frequency or voltage fluctuations occur in the utility grid (protective functions 81, 27-1, 59-1, 67-1, 67N-1). The protective relay obtains the measured values via a three-phase current and voltage transformer set and a single-phase connection to the generator voltage transformer (for synchronization). Circuit-breaker CB2 will be activated in case of disconnection. The transformer is protected by a differential protection and inverse and definite time overcurrent protection functions for the phase-to-phase currents. In the event of a fault, circuit-breaker CB1 in the utility grid will be activated via a remote link. Circuitbreaker CB2 is activated in addition. Time overcurrent protective functions protect the feeders 1 and 2 against short-circuits and overload caused by the connected consumers. The phase-to-phase currents and the zero currents of the feeders can be protected by inverse and definite time overcurrent protection elements. Circuit-breakers CB4 and CB5 are activated in the event of a fault. In addition, the busbar could be equipped with the 7UT635 differential protective relay for multiple ends. The current transformers required to this end are already included in Figure 2-91. Synchronization Before Connecting the Generator In most cases, it is the power customer who is responsible for restoring normal system operation after disconnection. The 7SJ64 relay tests whether the synchronous system conditions are satisfied. After successful synchronization the generator is connected to the busbar. The voltages required for synchronization are measured at the transformer and at the generator. The voltage at the transformer is measured in all three phases since they are also necessary to determine the direction. A generator supplies the phase-tophase voltage Vca across a star-delta transformer to device input V4 (see Figure 292). SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 276 2 Functions Wiring Diagram, Power Direction Figure 2-92 shows the wiring of the device for reverse-power protection and synchronization. The power flow in positive or forward direction occurs from the high-voltage busbar (not shown) via the transformer to the low-voltage busbar. Figure 2-92 277 Wiring diagram for a 7SJ642 as reverse-power protection (flush-mounted case) SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.18 Reverse-Power Protection Application with Flexible Protection Function 2.18.2 Implementation of the Reverse-Power Protection General The names of the indications can be edited in DIGSI and were tailored to this example. The parameter names are fixed. Determination of the Reverse Power The reverse-power protection evaluates the active power from the symmetrical fundamental components of voltages and currents. Evaluation of the positive-sequence systems secures reverse-power detection against asymmetries occurring in the voltages and currents and reflects the real load of the drive side. The calculated active power value corresponds to the total active power. The relay measures the power in direction of the busbar as being positive for the connection shown in the example. Functional Logic The following logic diagram depicts the functional logic of the reverse-power protection. Figure 2-93 Logic diagram of the reverse-power determination with flexible protection function The reverse-power protection picks up once the configured pickup threshold has been exceeded. If the pickup condition persists during the equally settable pickup delay, the pickup message P.rev.PU is generated and starts the trip delay time. If the pickup condition does not drop out while the trip delay time is counting down, the trip indication P. rev. TRIP and the timeout indication P. rev. timeout are generated. The picked up element drops out when the value falls below the dropout threshold. The blocking input >P rev. block blocks the entire function, i.e. pickup, trip and running times are reset. After the blocking has been released, the reverse power must exceed the pickup threshold and both times must run out before the protective function trips. Pickup Value, Dropout Ratio The pickup value of the reverse-power protection is set to 10% of the generator nominal output. In this example, the setting value is configured as secondary power in watts. The following relationship exists between the primary and the secondary power: SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 278 2 Functions On the basis of the indicated data, the pickup values are calculated considering P prim = 3.81 MW (10% of 38.1 MW) on the primary level to on the secondary level. The dropout ratio is set to 0.9. This yields a secondary dropout threshold of Psec, dropout = 15.6 W. If the pickup threshold is reduced to a value near the lower setting limit of 0.5 W, the dropout ratio should equally be reduced to approximately 0.7. Delay for Pickup, Dropout and Trip The reverse-power protection does not require short tripping times as protection from undesired power feedback. In the present example, it is useful to delay pickup and dropout by about 0.5 s and the trip by approx. 1 s. Delaying the pickup will minimize the number of fault logs which are opened when the reverse power oscillates around the threshold. When using the reverse-power protection to disconnect the switchgear quickly from the utility grid if faults occur, it is useful to select a larger pickup value (e.g. 50% of nominal power) and shorter time delays. 279 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.18 Reverse-Power Protection Application with Flexible Protection Function 2.18.3 Configuring the Reverse-Power Protection in DIGSI First create and open a 7SJ64x (e.g. 7SJ642) device in DIGSI Manager. Configure a flexible protection function (flexible function 01) for the present example in the Device Configuration (figure 2-94). Figure 2-94 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 Configuration of a flexible protection function 280 2 Functions Select Additional functions" in the Parameters" menu to view the flexible function (figure 2-95). Figure 2-95 The flexible function appears in the function selection. First activate the function at Settings --> General" and select the operating mode 3phase" (figure 2-96): Figure 2-96 Selection of the three-phase operating mode Select Active power reverse " and Overshooting" in the menu items Measured Quantity" and Measurement Method". Open the menu item Settings" and set a checkmark in the box Display additional settings" to configure threshold, pickup delay and trip delay (Figure 2-97). Since it is not possible to determine the power direction during a failure of the measuring voltage, it is useful to activate a blocking in this case. 281 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.18 Reverse-Power Protection Application with Flexible Protection Function Figure 2-97 Allocating the Reverse-Power Protection in DIGSI Configuration Matrix Setting options of the flexible function The DIGSI configuration matrix initially shows the following indications (after selecting Indications and commands only" and No filter", Figure 2-98): Figure 2-98 Indications prior to editing Clicking the texts allows short text and long text to be edited as required by the application (Figure 2-99): Figure 2-99 Indications after editing The indications are allocated in the same way as the indications of other protective functions. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 282 2 Functions 2.19 Synchronism and Voltage Check 25 (7SJ64 only) The synchronization function is only available for device 7SJ64. It has configuration options for four different synchronization functions. The function and operation is described in the following using the SYNC Function group 1. The same applies to function groups 2 to 4. 2.19.1 SYNC Function group 1 When connecting two sections of a power system, the synchronism check verifies that the start does not endanger the stability of the power system. Applications * Typical applications are, for example, the synchronism check of a feeder and a busbar (see Figure 2-100) or the synchronism check of two busbars via bus coupler (see Figure 2-101). Prerequisites The synchronism check is only available for 7SJ64. 2.19.1.1 General For comparing the two voltages the synchronism check uses the reference voltage V1 and an additional voltage to be connected V2. If a transformer is connected between the two voltage transformers (Figure 2-100), its vector group can be adapted in the 7SJ64 relay so that external adaptors are not required. Figure 2-100 283 Infeed SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.19 Synchronism and Voltage Check 25 (7SJ64 only) Figure 2-101 Bus coupler The synchronism check of 7SJ64 usually cooperates with the integrated automatic reclosing system and the control functions of the control function. It is also possible to employ an external automatic reclosing system. In such a case signal exchange between the devices is accomplished via binary inputs and outputs. The configuration decides whether the synchronism check is carried out only for automatic reclosing or only for circuit breaker control or both. It is also possible to specify different release criteria for automatic close or control close. Synchronous connection is always accomplished via the integrated control. The release command for closing under satisfied synchronism conditions can be deactivated by parameter 6x13 25 Synchron. The disabled closing release can, however, be activated via binary input (>25 synchr."). It is intended for special applications (seede-energized switching"). Connection, Multiple-phase For comparing the two voltages the synchronism check takes the reference voltage V1 and an additional voltage to be connected V2. The reference voltage V1 is derived from the multi-phase system, usually the three phase-ground voltages. The voltage to be synchronized V2 is assigned to the single-phase connection and may be any phaseground or phase-phase voltage. The device can also be connected in V-connection using two phase-phase voltages. In that case, a phase-to-phase voltage must be connected to the voltage to be synchronized V2. Please observe also that a V-connection does not allow the zero sequence voltage to be determined. The functions Directional Time Overcurrent Protection Ground", Directional Ground Fault Detection" and Fuse-Failure-Monitor (FFM)" must be disabled. Connection, Singlephase If there is only one primary voltage to represent the reference voltage V1, the device can be informed of this fact via the power system data. Also in this case the synchronism check can be fully applied. Operating Modes The synchronism check can be operated in two modes: * Synchrocheck * Synchronous / Asynchronous Synchronous power systems exhibit small differences regarding phase angle and voltage magnitude. Before connection it is checked whether conditions are synchronous or not. If synchronism prevails the system is energized, with asynchronous con- SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 284 2 Functions ditions it is not. The circuit breaker operating time is not taken into consideration. The SYNCHROCHECK mode is used. It corresponds to the classic synchrocheck function. On the other hand, asynchronous systems include bigger differences and the time window for switching passes relatively quick. It is useful to consider the operating time of the circuit breaker. The ASYN/SYNCHRON mode is used. Functional Sequence The synchrocheck function only operates if it receives a measurement request. This request may be issued by the control, the automatic reclosing function or externally via binary input, e.g. from an external automatic reclosing system. The measurement request performs certain plausibility checks (for further information see Plausibility Check"). If there is a condition which is not plausible, a message 25 Sync. Error" is output. The measurement is then not carried out. If conditions are plausible, measurement is initiated (message 25x meas."; with x = 1..n, according to the function group). Depending on the selected operating mode, the configured release conditions are then checked (see margin headings Synchrocheck" / Synchronous/Asynchronous"). Each condition met is indicated explicitly (messages 25 Vdiff ok", 25 fdiff ok", 25 diff ok"). Also conditions not fulfilled are indicated, for example, when voltage differences (messages 25 V2>V1", 25 V2f1", 25 f21", 25 2<1") lie outside the threshold values. For these messages to be sent, both voltages must lie within the operating range of the synchrocheck (see margin heading Operating Range"). If these conditions are met, the synchrocheck function issues a release signal for closing the breaker (25 CloseRelease"). This release signal is only available for the configured duration of the CLOSE command and is always processed by the control, which issues the actual CLOSE command for controlling the circuit breaker (see also margin heading Interaction with the control"). The annunciation 25 Synchron" is applied as long as the synchronous conditions are fulfilled. Measuring the synchronism conditions can be confined to a maximum monitoring time T-SYN. DURATION. If the conditions are not fulfilled during T-SYN. DURATION, the release is cancelled (message 25 MonTimeExc"). A new synchrocheck can only be performed if a new measurement request is received. Plausiblity Check / SYNC Error A parameter plausibility check is carried out upon device startup. Message 25 SetError" is displayed if a fault is detected. If an implausible condition is detected after a measurement request, message 25 Sync. Error" is generated. The measurement is not initiated in that case. The following plausibility checks are carried out: * Checking unique function group identification * Checking the configuration * Evaluation of monitoring functions If one and the same SYNC function group has multiple selections, error message 25 FG-Error" is output additionally. The synchrocheck cannot be bypassed via binary input. Concerning configuration it is also checked if power system address 213 is set to Van,Vbn,Vcn,VSy. Otherwise message 25 Sync. Error" is output. Furthermore, specific thresholds and settings of the selected function group are checked. If there is a condition which is not plausible, error message 25 Set-Error" is output additionally. Here, please make sure that Address 6x06 (threshold V1, V2 energized) 285 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.19 Synchronism and Voltage Check 25 (7SJ64 only) is smaller than Address 6x03 (lower voltage limit Vmin). The synchrocheck cannot be bypassed via binary input. If the monitoring function Fuse-Failure-Monitor is used and if it has picked up at the same time as the measurement of the synchronization was requested, the synchronization is not started either (message 25 Sync. Error"). The same applies, if a voltage transformer failure (m.c.b. tripping) is communicated to the device via binary inputs 6509 >FAIL:FEEDER VT" or 6510 >FAIL: BUS VT". In this case, the synchrocheck can be bypassed via binary input. Operating Range The operating range of the synchrocheck is defined by the configured voltage thresholds Vmin and Vmax, and the fixed frequency band fNom 3 Hz. If measurement is started and one or both voltages are outside the operating range, or one voltage leaves the permissible range, corresponding messages indicate this behaviour (25 f1>>", 25 f1<<", 25 V1>>", 25 V1<<", etc.). Measured Values The measured values of the synchrocheck are displayed in separate boxes for primary, secondary and percentage values. The measured values are displayed and updated only while a synchrocheck is requested. The following is displayed: * Value of reference voltage V1 * Value of the voltage to be synchronized V2 * Frequency values f1 and f2 * Differences of Voltage, Frequency and Angle. 2.19.1.2 Synchrocheck Having selected operating mode SYNCHROCHECK the mode verifies the synchronism before connecting the two system components and cancels the connecting process if parameters for synchronism lie outside the configured thresholds. Before a release is granted, the following conditions are checked: * Is the reference voltage V1 above the setting value Vmin but below the maximum voltage Vmax? * Is the voltage V2 to be synchronized above the setting value Vmin but below the maximum voltage Vmax? * Is the voltage difference V2 - V1 within the permitted threshold dV SYNCHK V2>V1? * Is the voltage difference V1 - V2 within the permitted threshold dV SYNCHK V2f1? * Is the frequency difference f1 - f2 within the permitted threshold df SYNCHK f21? * Is the angle difference 1 - 2 within the permitted threshold d SYNCHK 2<1? SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 286 2 Functions 2.19.1.3 Synchronous / Asynchronous The operating mode ASYN/SYNCHRON uses the frequency slip of the two power systems (parameter F SYNCHRON) to determine whether the power systems are asynchronous to each other ("Switching under Asynchronous System Conditions") or synchronous ("Switching under Synchronous System Conditions"). If systems are asynchronous, the time window for switching is passed relatively quickly. Therefore, it is reasonable to take into account the operating time of the circuit breaker. Thus the device can issue the ON command at a time where asynchronous conditions prevail. When the poles make contact the conditions will be synchronous. It is also possible to generally take into account the operating time of the circuit breaker, i.e. also with synchronous conditions prevailing. Switching under Synchronous System Conditions Switching under synchronous conditions means that the ON command will be released as soon as the characteristic data (voltage difference, angle difference) are within the thresholds specified by configuration. Before granting a release for closing under synchronous conditions, the following conditions are checked: * Is the reference voltage V1 above the setting value Vmin but below the maximum voltage Vmax? * Is the voltage V2 to be synchronized above the setting value Vmin but below the maximum voltage Vmax? * Is the voltage difference V2 - V1 within the permitted threshold dV SYNC V2>V1? * Is the voltage difference V1 - V2 within the permitted threshold dV SYNC V2 1? * Is the angle difference 1 - 2 within the permitted threshold d SYNC 2< 1? As soon as all synchronism conditions are fulfilled, the message 25 Synchron" is issued. Switching under Asynchronous System Conditions For switching under asynchronous system conditions the device determines the time for issuing the ON command from the angle difference and the frequency difference such that the voltages (of busbar and feeder) are identical at the instant the poles make contact. For this purpose the device must be informed of the operating time of the circuit breaker for closing. Before a release is granted, the following conditions are checked: * Is the reference voltage V1 above the setting value Vmin but below the maximum voltage Vmax? * Is the voltage V2 to be synchronized above the setting value Vmin but below the maximum voltage Vmax? * Is the voltage difference V2 - V1 within the permitted threshold dV ASYN V2>V1? * Is the voltage difference V1 - V2 within the permitted threshold dV ASYN V2f1? * Is the frequency difference f1 - f2 within the permitted threshold df ASYN f2. Thus, with a multiple-phase connection at side V1 all three voltages must have a higher value than threshold V> so that side V1 is recognized as energized. With single-phase connection, of course, only one voltage has to exceed the threshold value. Besides release under synchronous conditions, the following additional release conditions can be selected for the check: SYNC V1>V2< = Release on the condition that component V1 is energized and component V2 is de-energized. SYNC V1 = Release on the condition that component V1 is de-energized and component V2 is energized. SYNC V1V2< or SYNC V1 are fulfilled). Synchronization thus takes place by involving the additional parameter 6x13 25 Synchron (set to NO) also, e.g. for connecting a ground switch. In such a case, the switch may only be connected if no voltage applies on load side, i.e. connection is not permitted under synchronous conditions. The release conditions can be configured individually either for automatic reclosing or for manual closing via control commands. You can, for example, allow manual closing for synchronism or for de-energized feeder whereas before an automatic reclosing operation, checking only de-energized conditions at one feeder terminal and afterwards only synchronism at the other. The threshold below which a power system component is considered as de-energized is defined by parameter V<. If the measured voltage exceeds the threshold V>, a power system component is energized. Thus, with a multiple-phase connection at side V1 all three voltages must have a higher value than threshold V> so that side V1 is recognized as energized. With single-phase connection, of course, only one voltage has to exceed the threshold value. Before granting a release for connecting the energized component V1 and the de-energized component V2, the following conditions are checked: * Is the reference voltage V1 above the setting value Vmin and V> but below the maximum voltage Vmax? * Is the voltage to be synchronized V2 below the threshold V V2<", 25 V1< V2>" and 25 V1< V2<". Via binary input >25 V1>V2<", >25 V1" and >25 V125direct CO" this release can also be granted externally. Blocking the entire synchrocheck is possible via binary input >BLK 25-1". The message signaling this condition is made via 25-1 BLOCK". When blocking the measurement is terminated and the entire function is reset. A new measurement can only be performed with a new measurement request. Via binary input >BLK 25 CLOSE" it is possible to only block the release signal for closing (25 CloseRelease"). When blocking is active, measurement continues. The blocking is indicated by the message 25 CLOSE BLK". When blocking is reset and release conditions are fulfilled, the release signal for closing is issued. 2.19.1.6 SYNC Function Groups The 7SJ64 relay comprises 4 SYNC function groups (SYNC function group 1 to 4) whereby each group contains all setting parameters required by a SYNC function. This generally includes the switchgear component for which the SYNC function settings are to be applied. However, several SYNC function groups may be used for one point of synchronization/switching object if synchronismn is to be performed with different parameters. Allocation of switchgear component and SYNC function group must then be accomplished dynamically (whichever is the function group to operate with) via one of the binary inputs from >25-1 act" to >25-4 act". If the assignment to the SYNC groups is clear, the binary inputs are not required. Selecting one SYNC function group several times, causes output of error message (25 FG-Error"). 289 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.19 Synchronism and Voltage Check 25 (7SJ64 only) 2.19.1.7 Interaction with Control, AR and External Control With Control Basically, the synchrocheck interacts with the device control. The switchgear component to be synchronized is selected via a parameter. If an ON command is issued, the control takes into account that the switchgear component requires synchronism. The control sends a measurement request (25 Measu. req.") to the synchrocheck which is then started. Having completed the check, the synchrocheck issues the release message (25 CloseRelease") to which the control responds by terminating the switching operation positively or negatively (see Figure 2-102). Figure 2-102 SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 Interaction of control and synchrocheck 290 2 Functions With AR The automatic reclosing (AR) function can also interact with the synchronizing function. They are linked via the device control. The selection is made via parameter setting of the automatic reclosing function. The AR parameters (7138 Internal SYNC) determine which SYNC function group (SYNC FG) is used. The applicable switch is defined in the selected function group. The switchgear component indicated in the AR parameters (7137 Cmd.via control) and the selected SYNC function group should be identical. If their settings differ, the SYNC function group setting will overwrite that of the AR function. If no SYNC function group is entered in the AR parameter, the close command of the auto reclose function is carried out in unsynchronized form via the switchgear component indicated in the AR parameters. Equally, the close command 79 Close" (message 2851) allows only unsynchronized switching. If e.g. circuit breaker Q0 is configured as component to be switched synchronized, a CLOSE command of the AR function will address this breaker and assign it a CLOSE command which will be processed by the control. As this breaker requires synchronization, the control launches the synchronizing function and awaits release. If the configured conditions are fulfilled, the release is granted and the control issues the CLOSE command (see Figure 2-103). Figure 2-103 With External Control As another option the synchronizing function can be activated via external measurement request. The synchronizing function can be started via binary input using a measurement request (>25 Measu. Only" or pulse-like start and stop signals >25 Start" >25 Stop"). After the synchronizing function has completed the check, it issues a release message (25 CloseRelease"see Figure 2-104). Measurement is finished as soon as the measurement request is reset via the binary input. In this case there is no need to configure any control device to be synchronized. Figure 2-104 291 Connection of the automatic reclosing function to the synchrocheck Interaction of synchronizing function and external control SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 2.19 Synchronism and Voltage Check 25 (7SJ64 only) 2.19.1.8 Setting Notes General The synchrocheck function is only included in the 7SJ64 relay with its four voltage inputs. While setting the power system data 1 (see section 2.1.3.2) the device was already provided with data relevant for the measured values and the operating principle of the synchrocheck function. This concerns the following parameters: 202 Vnom PRIMARY primary nominal voltage of the voltage transformers V1 (phaseto-phase) in kV; 203 Vnom SECONDARY secondary nominal voltage of the voltage transformers V1 (phase-to-phase) in V; 213 VT Connect. 3ph defines the way voltage transformers are connected if there is more than one voltage transformer at the primary side. When using the synchronization function, setting Van,Vbn,Vcn,VSy must always be selected independent of whether there are phase-ground or phase-phase voltages at the primary side. Two phase-phase voltages are V-connected to the device (see also connection examples for 7SJ64 in the AppendixA.3). However, a zero sequence voltage cannot be determined in that case. The functions Directional Time Overcurrent Protection Ground", Directional Ground Fault Detection" and Fuse-FailureMonitor (FFM)" must be disabled. 240 VT Connect. 1ph specifies the voltage connected at side V1 if only one voltage transformer is available at the primary side. If the parameter is set different from NO, setting of address 213 is no more relevant. With single-phase connection the device generally assumes the voltage at the fourth voltage transformer (V4) as the voltage V2 to be synchronized. 214 Rated Frequency the operating range of the synchrocheck refers to the nominal frequency of the power system (fNom 3 Hz); The synchrocheck function can only operate if at least one of the addresses 161 25 Function 1 to 164 25 Function 4 is set to Enabled during configuration of the functional scope (see section 2.1.1.2). The operating mode can be preselected: ASYN/SYNCHRON means that switching will take place under synchronous and asynchronous conditions. SYNCHROCHECK corresponds to the classic synchrocheck function. If not required, this function is set to Disabled. A synchrocheck function group thus rendered ineffective is disabled in the menu item Synchronization; other groups in this menu are displayed. Only the corresponding messages of SYNC Function Group 1 are pre-allocated for IEC 60870-5-103 (VDEW). If other function groups (2 to 4) are configured and if their messages are to be disposed of via VDEW, they must first be configured to the system interface. Selecting one of the displayed SYNC function groups in DIGSI opens a dialog box with the tabs "General", "Power System Data", "asyn. operation", "syn. operation" and "Synchrocheck" in which the individual settings for synchronism can be made. For SYNC function group x the following holds: General Settings The general thresholds for the synchronizing function are set at addresses 6x01 to 6x12. Address 6x01 Synchronizing x can be set to switch the entire synchronizing function group x ON or OFF. If switched off, the synchronous check does not verify the synchronization conditions and release is not granted. SIPROTEC 4, 7SJ62/63/64 Handbuch C53000-G1140-C147-A, Edition 07.2015 292 2 Functions Address 6x02SyncCB is used to select the switchgear component to which the synchronizing settings will be applied. Select the option none to use the function as external synchronizing feature. It will then be triggered via binary input messages. Addresses 6x03Vmin and 6x04Vmax set the upper and lower limits for the operating voltage range V1 or V2 and thus determine the operating range for the synchronizing function. If the values leave this band, a message will be output. Address 6x05 V< indicates the voltage threshold below which the feeder or the busbar can safely be considered switched off (for checking a de-energized feeder or busbar). Address 6x06V> indicates the voltage threshold above which the feeder or busbar can safely be considered energized (for checking an energized feeder or busbar). It must be set below the anticipated operational undervoltage. The setting for the voltage values mentioned above is made secondary in volts. When using the PC and DIGSI for configuration, these values can also be entered as primary values. Depending on the connection of the voltages these are phase-to-ground voltages or phase-to-phase voltages. Addresses 6x07 to 6x10 are set to specify the release conditions for the closing check. Where: 6x07 SYNC V1 = Component V1 must be de-energized, component V2 must be energized (connection to reference without voltage, dead line); 6x08 SYNC V1>V2< = Component V1 must be energized, component V2 voltage value must be de-energized (connection to feeder without voltage, dead bus); 6x09 SYNC V1