GE D90 Plus Instruction Manual page 556

PHASOR MEASUREMENT UNIT
Frequency rate of change triggering
546
Dropout Time
Range: 0.00 to 600.00 seconds in steps of 0.01
Default: 1.00 seconds
This setting is 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 power
triggering function.
Events
Range: Enabled, Disabled
Default: Disabled
This setting enables and disables the logging of PMU power triggering events in the
sequence of events recorder.
The figure shows the logic for the PMU power triggering function.
This Phasor Measurement Unit triggering responds to the rate of change of frequency.
Separate thresholds are provided for rising and falling frequency. The trigger responds to
the rate of change of frequency (df/dt) of the PMU source.
Select the Settings > Metering > Phasor Measurement Unit > Triggering > df/dt Trigger
menu to open the PMU frequency rate of change triggering window.
Figure 478: Frequency rate of change triggering configuration settings
Figure 477: Power triggering logic
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 11: METERING