GE L60 Instruction Manual page 197

5 SETTINGS
c) ADVANCED FAULT DETECTORS MAIN MENU
PATH: SETTINGS GROUPED ELEMENTS
ADVANCED
FAULT DETECTORS
MESSAGE
MESSAGE
Three advanced fault detectors are provided.
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 increment in the magnitude 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 unbalance.
The positive-sequence current rate of change element responds to the increment in the magnitude 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.
All three detectors operate independently from each other, and independently from the instantaneous overcurrent FDL and
FDH comparators embedded in the 87PC function. Each detector supports the low and high setting levels to facilitate start-
ing 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. The advanced fault detec-
tors respond to their operating signals irrespective of the 87PC current configured.
d) NEGATIVE-SEQUENCE VOLTAGE FAULT DETECTION
PATH: SETTINGS GROUPED...
NEGATIVE SEQUENCE
VOLTAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
MESSAGE
The element responds to the magnitude of the I_2 × Z – V_2 voltage term in the signal source associated with the 87PC
function. The impedance factor is controlled by an independent setting. Two voltage thresholds are provided for the low-set
and high-set operation controlling keying and tripping, respectively.
• NEG SEQ VOL FD FUNCTION: This setting enables or disables the negative-sequence voltage fault detection. Note
that all fault detectors operate in parallel toward the 87PC function. If not required, a given fault detector shall be dis-
GE Multilin
PHASE COMPARISON ELEMENTS
NEGATIVE-SEQUENCE
VOLTAGE
RATE OF CHANGE OF
NEG SEQ CURRENT
RATE OF CHANGE OF
POS SEQ 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
NEG SEQ VOL FD
TARGET: Self-reset
NEG SEQ VOL FD
EVENTS: Disabled
L60 Line Phase Comparison Relay
5.5 GROUPED ELEMENTS
ADVANCED FAULT DETECTORS
See page 5–95.
See page 5–97.
See page 5–98.
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
Range: Self-Reset, Latched, Disabled
Range: Disabled, Enabled
5
5-95