GE L60, Инструкция по эксплуатации

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5-202 L60 LINE PHASE COMPARISON SYSTEM – INSTRUCTION MANUAL
GROUPED ELEMENTS CHAPTER 5: SETTINGS
5
5.6.3.5 Rate of change of negative-sequence current fault detection
SETTINGS  GROUPED ELEMENTS  SETTING GROUP 1(6)  PHASE COMPARISON ELEMENTS  ADVANCED FAULT
DETECTORS  RATE OF CHANGE OF NEG SEQ CURRENT
The element responds to the vector difference of the negative-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.
NEG SEQ di/dt FD FUNCTION
— This setting enables or disables the rate of change of negative-sequence current fault
detection. Note that all fault detectors operate in parallel toward the 87PC function. If not required, disable a given fault
detector. To effectively disable the overcurrent fault detectors under the main 87PC menu, set their threshold very high.
NEG SEQ di/dt FDL PICKUP
— This setting controls pickup of the low set stage of the element used to control the key
operation. The nominal current of the phase CT bank of the relay is 1 pu.
NEG SEQ di/dt FDL SEAL-IN
— This setting defines seal-in time of the FDL function. To equalize the response between all
terminals of the line, the timer is started at the rising edge of the raw di / dt condition.
NEG SEQ di/dt FDH PICKUP
— This setting controls pickup of the high set stage of the element used to control the trip
operation. The nominal current of the phase CT bank of the relay is 1 pu.
NEG SEQ di/dt FDH SEAL-IN
— This setting defines seal-in time of the FDH function. To equalize the response between all
terminals of the line, the timer is started at the rising edge of the raw di / dt condition. In this way, the fault detectors reset
approximately at the same time at all line terminals, regardless of responses of individual raw conditions potentially
different at different line terminals.
NEG SEQ FDH SUPV
— This setting provides seal-in control of the FDH function for the symmetrical external three-phase
faults starting as non-symmetrical defined by the
NEG SEQ di/dt FDH SEAL-IN
setting time. The overreaching distance
function typically is assigned with this setting.
NEG SEQ di/dt BLK
— Note that the fault detector is hard-wired to the 87PC scheme. It can be disabled permanently using
the function setting or blocked temporarily using this block setting. Select a FlexLogic operand that, if asserted, blocks this
fault detector.
NEG SEQ di/dt FD TARGET
— This setting controls targets of the function. These targets operate independently from the 87PC
targets.
NEG SEQ di/dt FD EVENTS
— This setting controls event recording of the function. These events are logged independently
from the 87PC events.

RATE OF CHANGE OF
 NEG SEQ CURRENT

NEG SEQ di/dt FD
FUNCTION: Disabled
Range: Disabled, Enabled

NEG SEQ di/dt FDL
PICKUP: 0.10 pu
Range: 0.01 to 5.00 pu in steps of 0.01

NEG SEQ di/dt FDL
SEAL-IN: 0.600 s
Range: 0.000 to 10.000 s in steps of 0.001

NEG SEQ di/dt FDH
PICKUP: 0.50 pu
Range: 0.01 to 5.00 pu in steps of 0.01

NEG SEQ di/dt FDH
SEAL-IN: 0.200 s
Range: 0.000 to 10.000 s in steps of 0.001

NEG SEQ FDH SUPV:
Off
Range: any FlexLogic operand

NEG SEQ di/dt BLK:
Off
Range: any FlexLogic operand

NEG SEQ di/dt FD
TARGET: Self-reset
Range: Self-Reset, Latched, Disabled

NEG SEQ di/dt FD
EVENTS: Disabled
Range: Disabled, Enabled