GE D60 Instruction Manual page 8

8 APPLICATION OF
SETTINGS
9 THEORY OF
OPERATION
10 MAINTENANCE
viii
7.2.1 Target messages...................................................................................................................7-7
7.2.2 Relay self-tests .......................................................................................................................7-7
8.1 Overview ........................................................................................................... 8-1
8.1.1 Introduction .............................................................................................................................8-1
8.1.2 Impact of memory polarization .....................................................................................8-1
8.1.3 High-set overcurrent elements ......................................................................................8-1
8.2 Distance elements (stepped distance scheme).......................................... 8-2
8.2.1 Phase distance.......................................................................................................................8-2
8.2.2 Ground distance....................................................................................................................8-3
8.3 Protection signaling schemes ....................................................................... 8-5
8.3.1 Overview ...................................................................................................................................8-5
8.3.2 Direct under-reaching transfer trip (DUTT) ...............................................................8-6
8.3.3 Permissive under-reaching transfer trip (PUTT)......................................................8-6
8.3.4 Permissive over-reaching transfer trip (POTT).........................................................8-6
8.3.5 Hybrid POTT scheme (HYB-POTT)...................................................................................8-7
8.3.6 Directional comparison blocking...................................................................................8-8
8.3.7 Directional comparison unblocking .............................................................................8-8
8.4 Series compensated lines ............................................................................8-10
8.4.1 Introduction .......................................................................................................................... 8-10
8.4.2 Distance.................................................................................................................................. 8-11
8.4.3 Ground directional overcurrent .................................................................................. 8-12
8.4.4 High-set phase overcurrent.......................................................................................... 8-12
8.5 Phase distance through power transformers ..........................................8-13
8.5.1 Phase distance protection............................................................................................. 8-13
8.5.2 Example.................................................................................................................................. 8-14
9.1 Distance elements........................................................................................... 9-1
9.1.1 Overview ...................................................................................................................................9-1
9.1.2 Phasor estimation.................................................................................................................9-2
9.1.3 Distance characteristics ....................................................................................................9-2
9.1.4 Fast distance algorithm .....................................................................................................9-7
9.1.5 Memory polarization ...........................................................................................................9-8
9.1.6 Distance elements analysis .............................................................................................9-9
9.2 Phase distance applied to power transformers.......................................9-12
9.2.1 Description ............................................................................................................................ 9-12
9.2.2 Example.................................................................................................................................. 9-16
9.3 Ground directional overcurrent..................................................................9-18
9.3.1 Description ............................................................................................................................ 9-18
9.3.2 Example.................................................................................................................................. 9-19
9.4 Series-compensated lines ............................................................................9-19
9.4.1 Description ............................................................................................................................ 9-19
9.5 Single-pole tripping.......................................................................................9-23
9.5.1 Overview ................................................................................................................................ 9-23
9.5.2 Phase selection ................................................................................................................... 9-26
9.5.3 Communications channels for pilot-aided schemes ........................................ 9-28
9.5.4 Permissive echo signaling.............................................................................................. 9-34
9.5.5 Pilot scheme / phase selector coordination.......................................................... 9-35
9.5.6 Cross-country fault example........................................................................................ 9-36
9.6 Fault locator ...................................................................................................9-37
9.6.1 Fault type determination................................................................................................ 9-37
10.1 Monitoring.......................................................................................................10-1
D60 LINE DISTANCE PROTECTION SYSTEM - INSTRUCTION MANUAL
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