GE L30

GE Multilin L30 Line Current Differential System 5-131
5 SETTINGS 5.4 SYSTEM SETUP
5
This element responds to frequency rate of change. 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.
• PMU 1 df/dt TRIGGER RAISE: This setting specifies the pickup threshold for the rate of change of frequency in the
raising direction (positive df/dt). The comparator applies a 4% hysteresis.
• PMU 1 df/dt TRIGGER FALL: This setting specifies the pickup threshold for the rate of change of frequency in the fall-
ing direction (negative df/dt). The comparator applies a 4% hysteresis.
• PMU 1 df/dt TRIGGER PKP TIME: This setting can be used to filter out spurious conditions and avoid unnecessary
triggering of the recorder.
• PMU 1 df/dt TRIGGER DPO TIME: This setting can be used to extend the trigger after the situation returned to nor-
mal. This setting is of particular importance when using the recorder in the forced mode (recording as long as the trig-
gering condition is asserted).