GE L60 Instruction Manual page 259

5 SETTINGS
c) ADVANCED FAULT DETECTORS MAIN MENU

PATH: SETTINGS GROUPED ELEMENTS
 ADVANCED
 FAULT DETECTORS
MESSAGE
MESSAGE
MESSAGE
MESSAGE
Five advanced fault detectors are provided, which are supervised by the condition that magnitude of mixed current has to
be above 0.02 pu.
The negative-sequence voltage element responds to the I × Z – V term for negative-sequence voltage and current and is
meant to detect faults under weak system conditions.
The negative-sequence current rate of change element responds to the vector difference of the negative-sequence current
over a half-a-cycle moving data window, and is meant to detect faults under load unbalance such as on untransposed high
voltage transmission lines or in a vicinity of electrical traction systems causing significant negative-sequence current unbal-
ance.
The positive-sequence current rate of change element responds to the vector difference of the positive-sequence current
over a half-a-cycle moving data window, and is meant to detect three-phase balance faults under high load conditions.
The negative-sequence current overcurrent element responds to the increment of the negative-sequence current above
threshold.
The positive-sequence current overcurrent element responds to the increment of the positive-sequence current above
threshold.
All advanced fault detectors operate independently from each other, and independently from the mixed signal overcurrent
FDL and FDH comparators embedded in the 87PC function. Each detector supports the low and high setting levels to facil-
itate starting and supervise tripping. When enabled, a given detector is automatically used to control the 87PC function.
Effectively all detectors are ORed before they are routed to the 87PC element.
The overcurrent fault detectors respond to the effective operating current of the 87PC function, which includes charging
current compensation. The advanced fault detectors respond to their operating signals irrespective of the configured 87PC
current.
d) NEGATIVE-SEQUENCE VOLTAGE FAULT DETECTION

PATH: SETTINGS GROUPED...
 NEGATIVE SEQUENCE
 VOLTAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
GE Multilin

PHASE COMPARISON ELEMENTS
 NEGATIVE-SEQUENCE
 VOLTAGE
 RATE OF CHANGE OF
 NEG SEQ CURRENT
 RATE OF CHANGE OF
 POS SEQ CURRENT
 NEGATIVE SEQUENCE
 CURRENT
 POSITIVE SEQUENCE
 CURRENT
 
PHASE COMPARISON... ADVANCED FAULT DETECTORS
NEG SEQ VOL FD
FUNCTION: Disabled
NEG SEQ VOL FD
IMPEDANCE: 10.0%
NEG SEQ VOL FDL
PICKUP: 0.010 pu
NEG SEQ VOL FDH
PICKUP: 0.050 pu
NEG SEQ VOL FD BLK:
Off
L60 Line Phase Comparison System
5.5 GROUPED ELEMENTS

ADVANCED FAULT DETECTORS
See page 5–121.
See page 5–123.
See page 5–124.
See page 5–126.
See page 5–127.

NEGATIVE SEQUENCE VOLTAGE
Range: Disabled, Enabled
Range: 0.0 to 100% in steps of 0.1
Range: 0.005 to 3.000 pu in steps of 0.001
Range: 0.005 to 3.000 pu in steps of 0.001
Range: any FlexLogic™ operand
5
5-121