GE D90 Plus Instruction Manual page 494

PHASOR MEASUREMENT UNIT
Frequency rate of change triggering
486
Dropout Time
Range: 0.00 to 600.00 seconds in steps of 0.01
Default: 1.00 seconds
This setting may be used to extend the trigger after the situation returned to normal.
This setting is of particular 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 phasor
measurement unit power triggering function.
Events
Range: Enabled, Disabled
Default: Disabled
This setting enables and disables the logging of phasor measurement unit power
triggering events in the sequence of events recorder.
The logic for the phasor measurement unit power triggering function is shown below.
Figure 411: Phasor measurement unit power triggering logic
This phasor measurement unit frequency rate of change triggering function responds to
the rate of change of frequency. Separate thresholds are provided for rising and dropping
frequency. The trigger responds to the rate of change of frequency (df/dt) of the phasor
measurement unit (PMU) source.
Select the Settings > Metering > Phasor Measurement Unit > Triggering > df/dt Trigger
menu item to open the phasor measurement unit frequency rate of change triggering
window.
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 11: METERING