GE L90 Instruction Manual page 7

7. COMMANDS AND
TARGETS
8. SECURITY
9. THEORY OF OPERATION
GE Multilin
TABLE OF CONTENTS
6.4.5 PHASOR MEASUREMENT UNIT RECORDS................................................. 6-25
6.4.6 BREAKER MAINTENANCE ............................................................................. 6-26
6.5 PRODUCT INFORMATION
6.5.1 MODEL INFORMATION .................................................................................. 6-27
6.5.2 FIRMWARE REVISIONS ................................................................................. 6-27
7.1 COMMANDS
7.1.1 COMMANDS MENU .......................................................................................... 7-1
7.1.2 VIRTUAL INPUTS.............................................................................................. 7-1
7.1.3 CLEAR RECORDS ............................................................................................ 7-2
7.1.4 SET DATE AND TIME ....................................................................................... 7-2
7.1.5 RELAY MAINTENANCE .................................................................................... 7-3
7.1.6 PHASOR MEASUREMENT UNIT ONE-SHOT.................................................. 7-3
7.1.7 SECURITY ......................................................................................................... 7-5
7.2 TARGETS
7.2.1 TARGETS MENU............................................................................................... 7-6
7.2.2 TARGET MESSAGES ....................................................................................... 7-6
7.2.3 RELAY SELF-TESTS......................................................................................... 7-6
8.1 USER ACCOUNTS
8.1.1 OVERVIEW........................................................................................................ 8-1
8.1.2 ENABLING THE SECURITY MANAGEMENT SYSTEM ................................... 8-1
8.1.3 ADDING A NEW USER ..................................................................................... 8-1
8.1.4 MODIFYING USER PRIVILEGES ..................................................................... 8-2
8.2 CYBERSENTRY
8.2.1 OVERVIEW........................................................................................................ 8-4
8.2.2 SECURITY MENU ............................................................................................. 8-6
9.1 OVERVIEW
9.1.1 L90 DESIGN ...................................................................................................... 9-1
9.1.2 L90 ARCHITECTURE ........................................................................................ 9-1
9.1.3 REMOVAL OF DECAYING OFFSET................................................................. 9-2
9.1.4 PHASELET COMPUTATION............................................................................. 9-2
9.1.5 DISTURBANCE DETECTION............................................................................ 9-3
9.1.6 FAULT DETECTION .......................................................................................... 9-3
9.1.7 GROUND DIFFERENTIAL ELEMENT............................................................... 9-4
9.1.8 CLOCK SYNCHRONIZATION ........................................................................... 9-5
9.1.9 FREQUENCY TRACKING AND PHASE LOCKING .......................................... 9-6
9.1.10 FREQUENCY DETECTION ............................................................................... 9-7
9.1.11 PHASE DETECTION ......................................................................................... 9-7
9.1.12 PHASE LOCKING FILTER .............................................................................. 9-10
9.1.13 MATCHING PHASELETS................................................................................ 9-11
9.1.14 START-UP ....................................................................................................... 9-11
9.1.15 HARDWARE AND COMMUNICATION REQUIREMENTS ............................. 9-11
9.1.16 ONLINE ESTIMATE OF MEASUREMENT ERRORS ..................................... 9-12
9.1.17 CT SATURATION DETECTION ...................................................................... 9-13
9.1.18 CHARGING CURRENT COMPENSATION ..................................................... 9-13
9.1.19 DIFFERENTIAL ELEMENT CHARACTERISTICS........................................... 9-14
9.1.20 RELAY SYNCHRONIZATION.......................................................................... 9-15
9.2 OPERATING CONDITION CHARACTERISTICS
9.2.1 DESCRIPTION................................................................................................. 9-16
9.2.2 TRIP DECISION EXAMPLE............................................................................. 9-18
9.2.3 TRIP DECISION TEST .................................................................................... 9-18
9.3 DISTANCE ELEMENTS
9.3.1 INTRODUCTION.............................................................................................. 9-20
9.3.2 PHASOR ESTIMATION ................................................................................... 9-20
9.3.3 DISTANCE CHARACTERISTICS .................................................................... 9-21
L90 Line Current Differential System vii