5-158
C70 Capacitor Bank Protection and Control System
GE Multilin
5.6 GROUPED ELEMENTS
5 SETTINGS
5
Up to three identical neutral voltage unbalance elements, one per each VT bank configured in hardware, are provided.
The element responds to the voltage signal at the neutral point of the capacitor bank. The operating equations are properly
compensated for both the system unbalance such as during close-in external faults, and the inherent bank unbalance. The
bus zero-sequence voltage required for compensation of the system unbalance can be measured internally to the relay
from phase voltages, or delivered as a 3V0 signal from an open-corner-delta VT via an auxiliary voltage channel of the
relay.
Compensation for the inherent unbalance of the protected bank uses the B and C phase voltages, and thus this function
requires wye connected phase VTs. The inherent unbalance is zeroed out using ratios of the reactances between the refer-
ence phase A, and the two other phases. An automatic setting procedure is available under the
COMMAND
menu to calcu-
late the compensating factors automatically when installing the relay, or after repairs of the bank.
To enhance performance under large system unbalances when the neutral-point and system zero-sequence voltages may
become significant, a concept of a restraint is introduced. The slope of the operating characteristic is user adjustable, and if
desired, it can be effectively removed yielding a straight compensated overvoltage function.
For additional information refer to the
Theory of operation
and
Application of settings
chapters.
MESSAGE
NTRL VOL UNBAL 1
STG 2 SLOPE: 0.0%
Range: 0.0 to 10.0% in steps of 0.1
MESSAGE
NTRL VOL UNBAL 1
STG 3 PKP: 0.020 pu
Range: 0.001 to 1.000 pu in steps of 0.001
MESSAGE
NTRL VOL UNBAL 1
STG 3 SLOPE: 5.0%
Range: 0.0 to 10.0% in steps of 0.1
MESSAGE
NTRL VOL UNBAL 1
STG 4 PKP: 0.030 pu
Range: 0.001 to 1.000 pu in steps of 0.001
MESSAGE
NTRL VOL UNBAL 1
STG 4 SLOPE: 5.0%
Range: 0.0 to 10.0% in steps of 0.1
MESSAGE
NTRL VOL UNBAL 1 STG
1 PKP DELAY: 30.00 s
Range: 0.00 to 600.00 s in steps of 0.01
MESSAGE
NTRL VOL UNBAL 1 STG
2 PKP DELAY: 10.00 s
Range: 0.00 to 600.00 s in steps of 0.01
MESSAGE
NTRL VOL UNBAL 1 STG
3 PKP DELAY: 1.00 s
Range: 0.00 to 600.00 s in steps of 0.01
MESSAGE
NTRL VOL UNBAL 1 STG
4 PKP DELAY: 0.20 s
Range: 0.00 to 600.00 s in steps of 0.01
MESSAGE
NTRL VOL UNBAL 1
DPO DELAY: 0.25 s
Range: 0.00 to 600.00 s in steps of 0.01
MESSAGE
NTRL VOL 1 BLK STG1:
Off
Range: FlexLogic™ operand
MESSAGE
NTRL VOL 1 BLK STG2:
Off
Range: FlexLogic™ operand
MESSAGE
NTRL VOL 1 BLK STG3:
Off
Range: FlexLogic™ operand
MESSAGE
NTRL VOL 1 BLK STG4:
Off
Range: FlexLogic™ operand
MESSAGE
NTRL VOL UNBAL 1
TARGET: Self-Reset
Range: Self-reset, Latched, Disabled
MESSAGE
NTRL VOL UNBAL 1
EVENTS: Disabled
Range: Disabled, Enabled
Summary of Contents for UR Series C70
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Page 10: ...x C70 Capacitor Bank Protection and Control System GE Multilin TABLE OF CONTENTS ...
Page 344: ...5 220 C70 Capacitor Bank Protection and Control System GE Multilin 5 10 TESTING 5 SETTINGS 5 ...
Page 586: ...D 10 C70 Capacitor Bank Protection and Control System GE Multilin D 1 OVERVIEW APPENDIXD D ...