GE D90 Plus Instruction Manual page 552

PHASOR MEASUREMENT UNIT
542
Function
Range: Enabled, Disabled
Default: Disabled
This setting enables and disables the PMU voltage triggering function.
Low Voltage
Range: 0.250 to 1.250 pu in steps of 0.001
Default: 0.800 pu
This setting specifies the low threshold for the abnormal voltage trigger, in per-unit
values of the PMU source. A value of 1 pu is a nominal voltage value defined as the
nominal secondary voltage times VT ratio. The comparator applies a 3% hysteresis.
High Voltage
Range: 0.750 to 1.750 pu in steps of 0.001
Default: 1.200 pu
This setting specifies the high threshold for the abnormal voltage trigger, in per-unit
values of the PMU source. A value of 1 pu is a nominal voltage value defined as the
nominal secondary voltage times VT ratio. The comparator applies a 3% hysteresis.
Pickup Time
Range: 0.00 to 600.00 seconds in steps of 0.01
Default: 0.10 seconds
This setting can be used to filter out spurious conditions and avoid unnecessary
triggering of the recorder.
Dropout Time
Range: 0.00 to 600.00 seconds in steps of 0.01
Default: 1.00 seconds
This setting can be used to extend the trigger after the situation returns to normal. This
setting is of importance when using the recorder in the forced mode (recording as long
as the triggering condition is asserted).
Block
Range: any metering logic operand or shared operand
Default: OFF
Assertion of the operand assigned to this setting blocks operation of the PMU voltage
triggering function.
Events
Range: Enabled, Disabled
Default: Disabled
This setting enables and disables the logging of PMU voltage triggering events in the
sequence of events recorder.
The figure shows the logic for the PMU voltage triggering function.
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 11: METERING