CHAPTER 5: SETTINGS
GROUPED ELEMENTS
L60 LINE PHASE COMPARISON SYSTEM – INSTRUCTION MANUAL
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5
Figure 5-101: Negative-sequence current rate of change fault detector logic
5.6.3.6 Rate of change of positive-sequence current fault detection
SETTINGS
GROUPED ELEMENTS
SETTING GROUP 1(6)
PHASE COMPARISON ELEMENTS
ADVANCED FAULT
DETECTORS
RATE OF CHANGE OF POS SEQ CURRENT
The element responds to the vector difference of the positive-sequence current phasors taken at the present moment and
one-half a power system cycle earlier. Two current thresholds are provided for the low-set and high-set operation
controlling keying and tripping. The raw di / dt condition of the element detects the change and resets when reaching a
steady state fault condition. As such, a seal-in timer is provided to maintain the detected fault condition for a user
specified period of time.
POS SEQ di/dt FD FUNCTION
— This setting enables or disables the rate of change of positive-sequence current fault
detection. Note that all fault detectors operate in parallel toward the 87PC function. If not required, a given fault detector
shall be disabled. To effectively disable the overcurrent fault detectors under the main 87PC menu, set their threshold very
high.
POS SEQ di/dt FDL PICKUP
— This setting controls pickup of the low set stage of the element used to control the key
operation. Nominal current of the phase CT bank of the relay is 1 pu.
RATE OF CHANGE OF
POS SEQ CURRENT
POS SEQ di/dt FD
FUNCTION: Disabled
Range: Disabled, Enabled
POS SEQ di/dt FDL
PICKUP: 0.10 pu
Range: 0.01 to 5.00 pu in steps of 0.01
POS SEQ di/dt FDL
SEAL-IN: 0.600 s
Range: 0.000 to 10.000 s in steps of 0.001
POS SEQ di/dt FDH
PICKUP: 0.50 pu
Range: 0.01 to 5.00 pu in steps of 0.01
POS SEQ di/dt FDH
SEAL-IN: 0.200 s
Range: 0.000 to 10.000 s in steps of 0.001
POS SEQ FDH SUPV:
Off
Range: any FlexLogic operand
POS SEQ di/dt BLK:
Off
Range: any FlexLogic operand
POS SEQ di/dt FD
TARGET: Self-reset
Range: Self-Reset, Latched, Disabled
POS SEQ di/dt FD
EVENTS: Disabled
Range: Disabled, Enabled