Frequency Metering; Tracking Frequency - GE D90 Plus Instruction Manual

METERED VALUES

Frequency metering

Tracking frequency

570
Positive varhour, Negative varhour
Range: 0.000 to 1000000000000.000 varh in steps of 0.001
These actual values display the metered reactive energy for each applicable source.
Select the Actual Values > Metering > Frequency menu item to open the metered
frequency window. Source frequency is measured via software-implemented zero-crossing
detection of an AC signal. The signal is either a Clarke transformation of three-phase
voltages or currents, auxiliary voltage, or ground current as per the source configuration.
The signal used for frequency estimation is low-pass filtered. The final frequency
measurement is passed through a validation filter that eliminates false readings due to
signal distortions and transients.
Figure 497: Frequency metering window
The following actual values are available for each applicable source.
Name
Range: up to 20 alphanumeric characters
This value displays the user-programmed name for each source.
Frequency
Range: 0.000 to 90.000 Hz in steps of 0.001
These actual values display the metered frequency for each applicable source.
Select the Actual Values > Metering > Tracking Frequency menu item to open the
tracking frequency window.
Figure 498: Tracking frequency window
The following actual value is available.
Tracking Frequency
Range: 0.00 to 90.00 Hz in steps of 0.01
This actual value displays the tracking frequency. The frequency is tracked based on the
selection of the reference source with the
Settings > Protection > Power System > Frequency menu.
For additional information, refer to:
Power system frequency
Frequency And Phase Reference
on page 175
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 11: METERING
setting in the