GE D90 Plus Instruction Manual page 8

13 SECURITY
14 TESTING
15 THEORY OF
OPERATION
16 MAINTENANCE
viii
Pre-configured mimic diagrams........................................................................................................560
Metering summary editor ........................................................................................ 564
User-programmable pushbuttons ......................................................................... 567
User-programmable pushbutton operation ................................................................................568
User-programmable pushbuttons settings..................................................................................569
User-programmable pushbuttons editor ......................................................................................572
Password security ..................................................................................................... 575
Password security settings...................................................................................................................576
Password security operation...............................................................................................................578
EnerVista security management system .............................................................. 579
Enabling the security management system ................................................................................579
Adding a new user....................................................................................................................................579
Modifying user privileges.......................................................................................................................580
Test mode ................................................................................................................... 583
Force contact inputs................................................................................................................................583
Force contact outputs ............................................................................................................................584
Self-tests ..................................................................................................................... 585
Self-test error messages .......................................................................................................................586
Shared operands ....................................................................................................... 590
Shared self-test operands ....................................................................................................................591
Self-test logic operands .........................................................................................................................592
Plus
The D90 distance elements................................................................................ 595
Distance element arming logic ..........................................................................................................595
Distance element time domain algorithm ....................................................................................596
Distance element frequency domain algorithm ........................................................................596
Distance supervision ...............................................................................................................................597
Distance characteristics ........................................................................................................................598
Memory polarization ...............................................................................................................................604
Distance elements analysis..................................................................................................................605
Phase distance applied to power transformers .................................................. 610
Example system with power transformers...................................................................................613
Ground directional overcurrent theory................................................................. 615
Ground directional overcurrent example ......................................................................................616
Series compensated lines ........................................................................................ 616
Memory polarized directional comparators.................................................................................617
Dynamic reach control...........................................................................................................................618
Single-pole tripping................................................................................................... 620
SLG fault scenario for single-pole tripping....................................................................................622
SLG fault evolving into an LLG fault scenario for single-pole tripping.............................623
Phase selection ..........................................................................................................................................624
Communications channels for pilot-aided schemes ...............................................................625
Permissive echo signaling.....................................................................................................................632
Pilot scheme and phase selector coordination ..........................................................................633
Cross-country fault example...............................................................................................................634
General maintenance ............................................................................................... 637
Back up and restore settings .................................................................................. 637
Back up settings ........................................................................................................................................637
Restore settings .........................................................................................................................................638
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM - INSTRUCTION MANUAL
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