GE Multilin
L90 Line Current Differential System
5-285
5 SETTINGS
5.7 CONTROL ELEMENTS
5
f) CT FAILURE DETECTOR
PATH: SETTINGS
CONTROL ELEMENTS
MONITORING ELEMENTS
CT FAILURE DETECTOR
The CT failure function is designed to detect problems with system current transformers used to supply current to the relay.
This logic detects the presence of a zero-sequence current at the supervised source of current without a simultaneous
zero-sequence current at another source, zero-sequence voltage, or some protection element condition.
The CT failure logic (see below) is based on the presence of the zero-sequence current in the supervised CT source and
the absence of one of three or all of the three following conditions.
1.
Zero-sequence current at different source current (may be different set of CTs or different CT core of the same CT).
2.
Zero-sequence voltage at the assigned source.
3.
Appropriate protection element or remote signal.
The CT failure settings are described below.
•
CT FAIL FUNCTION:
This setting enables or disables operation of the CT failure element.
•
CT FAIL BLOCK:
This setting selects a FlexLogic operand to block operation of the element during some condition
(for example, an open pole in process of the single pole tripping-reclosing) when CT fail should be blocked. Local sig-
nals or remote signals representing operation of some remote current protection elements via communication chan-
nels can also be chosen.
•
CT FAIL 3I0 INPUT 1:
This setting selects the current source for input 1. The most critical protection element should
also be assigned to the same source.
•
CT FAIL 3I0 INPUT 1 PICKUP:
This setting selects the 3I_0 pickup value for input 1 (the main supervised CT source).
•
CT FAIL 3I0 INPUT 2
: This setting selects the current source for input 2. Input 2 should use a different set of CTs or a
different CT core of the same CT. If 3I_0 does not exist at source 2, then a CT failure is declared.
•
CT FAIL 3I0 INPUT 2 PICKUP
: This setting selects the 3I_0 pickup value for input 2 (different CT input) of the relay.
•
CT FAIL 3V0 INPUT:
This setting selects the voltage source.
CT FAILURE
DETECTOR
CT FAIL FUNCTION:
Disabled
Range: Disabled, Enabled
MESSAGE
CT FAIL BLOCK:
Off
Range: FlexLogic operand
MESSAGE
CT FAIL 3I0 INPUT 1:
SRC 1
Range: SRC 1, SRC 2, SRC 3, SRC 4
MESSAGE
CT FAIL 3I0 INPUT 1
PKP: 0.20 pu
Range: 0.00 to 2.00 pu in steps of 0.01
MESSAGE
CT FAIL 3I0 INPUT 2:
SRC 2
Range: SRC 1, SRC 2, SRC 3, SRC 4
MESSAGE
CT FAIL 3I0 INPUT 2
PKP: 0.20 pu
Range: 0.00 to 2.00 pu in steps of 0.01
MESSAGE
CT FAIL 3V0 INPUT:
SRC 1
Range: SRC 1, SRC 2, SRC 3, SRC 4
MESSAGE
CT FAIL 3V0 INPUT
PKP: 0.20 pu
Range: 0.00 to 2.00 pu in steps of 0.01
MESSAGE
CT FAIL PICKUP
DELAY: 1.000 s
Range: 0.000 to 65.535 s in steps of 0.001
MESSAGE
CT FAIL TARGET:
Self-reset
Range: Self-reset, Latched, Disabled
MESSAGE
CT FAIL EVENTS:
Disabled
Range: Disabled, Enabled
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 ...
