GE Multilin
L90 Line Current Differential System
2-3
2 PRODUCT DESCRIPTION
2.1 INTRODUCTION
2
2.1.2 FEATURES
LINE CURRENT DIFFERENTIAL:
•
Phase segregated, high-speed digital current differential system
•
Overhead and underground AC transmission lines, series compensated lines
•
Two-terminal and three-terminal line applications
•
Zero-sequence removal for application on lines with tapped transformers connected in a grounded wye on the line side
•
GE phaselets approach based on the Discrete Fourier Transform with 64 samples per cycle and transmitting two time-
stamped phaselets per cycle
•
Adaptive restraint approach improving sensitivity and accuracy of fault sensing
•
Increased security for trip decision using disturbance detector and trip output logic
•
Accommodates in-zone transformer with a magnitude and phase compensation and second harmonic inhibit during
transformer magnetizing inrush
•
Continuous clock synchronization via the distributed synchronization technique
•
Increased transient stability through DC decaying offset removal
•
Accommodates up to five times CT ratio differences
•
Peer-to-peer (master-master) architecture changing to master-slave via DTT (if channel fails) at 64 kbps
•
Charging current compensation
•
Interfaces direct fiber, multiplexed RS422, IEEE C37.94, and G.703 connections with relay ID check
•
Per-phase line differential protection direct transfer trip plus eight user-assigned pilot signals via the communications
channel
•
Secure 32-bit CRC protection against communications errors
•
Channel asymmetry (up to 10 ms) compensation using GPS satellite-controlled clock
BACKUP PROTECTION:
•
DTT provision for pilot schemes
•
Five zones of distance protection with six pilot schemes, power swing blocking and out-of-step tripping, line pickup,
and load encroachment
•
Two-element time overcurrent and two-element instantaneous overcurrent directional phase overcurrent protection
•
Two-element time overcurrent and two-element instantaneous overcurrent directional zero-sequence protection
•
Two-element time overcurrent and two-element instantaneous overcurrent negative-sequence overcurrent protection
•
Undervoltage and overvoltage protection
ADDITIONAL PROTECTION:
•
Breaker failure protection
•
Stub bus protection
•
VT and CT supervision
•
GE Multilin
sources
approach allowing grouping of different CTs and VTs from multiple input channels
•
Open pole detection
•
Breaker trip coil supervision and
seal-in
of trip command
•
FlexLogic allowing creation of user-defined distributed protection and control logic
CONTROL:
•
One and two breaker configuration for breaker-and-a-half and ring bus schemes, pushbutton control from the relay
•
Auto-reclosing and synchrochecking
Summary of Contents for UR Series L90
Page 652: ...A 16 L90 Line Current Differential System GE Multilin A 1 PARAMETER LISTS APPENDIX A A ...
Page 772: ...B 120 L90 Line Current Differential System GE Multilin B 4 MEMORY MAPPING APPENDIX B B ...
Page 802: ...C 30 L90 Line Current Differential System GE Multilin C 7 LOGICAL NODES APPENDIX C C ...
Page 812: ...D 10 L90 Line Current Differential System GE Multilin D 1 IEC 60870 5 104 APPENDIX D D ...
Page 824: ...E 12 L90 Line Current Differential System GE Multilin E 2 DNP POINT LISTS APPENDIX E E ...
Page 834: ...F 10 L90 Line Current Differential System GE Multilin F 3 WARRANTY APPENDIX F F ...
Page 846: ...xii L90 Line Current Differential System GE Multilin INDEX ...