Toshiba GR200 Series - Page 6

6F2S1914 (0.49)
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Contents
1 Introduction ......................................................................................................................................... 1
Protection functions ...................................................................................................................... 2
1.1.1 Purposes of the protection ..................................................................................................... 2
1.1.2 Requirements in the protection functions ............................................................................ 2
1.1.3 Behavior of backup protections ............................................................................................. 4
1.1.4 Concepts of current differential protection (DIF) function .................................................. 6
1.1.5 Concepts of distance protection (ZS/ZG) function ................................................................ 6
1.1.6 Concepts of carrier command protection (DISCAR/DEFCAR) function ........................... 10
1.1.7 Tripping CB by the protection functions .............................................................................. 10
1.1.8 Autoreclosing CB (ARC) after the operation of the protection functions ........................... 11
1.1.9 Conventional applications .................................................................................................... 11
Control......................................................................................................................................... 12
1.2.1 General control function ...................................................................................................... 12
1.2.2 Control and monitoring application .................................................................................... 12
Monitoring and metering functions ........................................................................................... 13
Hardware overview ..................................................................................................................... 14
Symbols used in logical diagrams .............................................................................................. 15
Abbreviation................................................................................................................................ 19
Function Block (FB), Function ID, Signal number (Data ID) .................................................. 21
2 Relay application ............................................................................................................................... 23
Current differential protection for the line ............................................................................... 24
Segregated-phase current differential protection function (DIFL) .......................................... 25
2.2.1 Differential protection characteristics (DIFL) ................................................................... 26
2.2.2 Check relays characteristics (OCs and UVs) ...................................................................... 32
2.2.3 CT circuit-failure detection (DIFL-CTF) ............................................................................ 34
2.2.4 Charging-current compensation (DIFL-Ic) ......................................................................... 35
2.2.5 Differential current monitor (DIFL-IDSV) ......................................................................... 37
2.2.6 Setting .................................................................................................................................. 38
2.2.7 Data ID ................................................................................................................................ 39
Zero-sequence current differential protection (DIFGL) ............................................................ 41
2.3.1 Differential protection characteristics (DIFGL) ................................................................. 41
2.3.2 Check relay characteristic (EFD)........................................................................................ 46
2.3.3 CT circuit-failure detection (DIFGL-CTF) ......................................................................... 47
2.3.4 Charging-current compensation (DIFGL-Ic) ...................................................................... 48
CT saturation countermeasure in DIFL (CTsat in DIFL) ........................................................ 49
2.4.1 Stabilization for CT saturation owing to through-fault current ....................................... 49
2.4.2 Settings against CT saturation ........................................................................................... 52
2.4.3 Setting .................................................................................................................................. 54