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2-16
L90 Line Current Differential System
GE Multilin
2.2 PILOT CHANNEL RELAYING
2 PRODUCT DESCRIPTION
2
•
Performs all functions of a slave L90
•
Receives current phasor information from all relays
•
Performs the current differential algorithm
•
Sends a current differential DTT signal to all L90 relays on the protected line
In the peer-to-peer mode, all L90 relays act as masters.
Figure 2–2: COMMUNICATIONS PATHS
2.2.2 CHANNEL MONITOR
The L90 has logic to detect that the communications channel is deteriorating or has failed completely. This can provide an
alarm indication and disable the current differential protection. Note that a failure of the communications from the master to
a slave does not prevent the master from performing the current differential algorithm; failure of the communications from a
slave to the master will prevent the master from performing the correct current differential logic. Channel propagation delay
is being continuously measured and adjusted according to changes in the communications path. Every relay on the protec-
tion system can assigned an unique ID to prevent advertent loopbacks at multiplexed channels.
IED-1
IED-1
IED-2
IED-2
IED-3
CHn
CHn
CHn
CHn
CHn
CHn
CHn
CHn
CHn
CHn
Rx
Rx
Optional redundant channel
Typical two-terminal application
Typical three-terminal application
Rx
Rx
Rx
Rx
Rx
Rx
Rx
Rx
Tx
Tx
Tx
Tx
Tx
Tx
Tx
Tx
Tx
Tx
831009A5.CDR
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 ...