GE L90 Instruction Manual page 476

GROUPED ELEMENTS CHAPTER 5: SETTINGS
T = Operating Time
TDM = Time Delay Multiplier (delay in seconds)
V = fundamental RMS value of voltage (pu)
F = frequency of voltage signal (pu)
Pickup = volts-per-hertz pickup setpoint (pu)
The figure shows the volts/hertz inverse A curves.
Figure 5-162: Volts-per-hertz curves, inverse curve A
5
Inverse curve B
The curve for the Volts/Hertz Inverse Curve B shape is derived from the formula:
Eq. 5-38
where
T = Operating Time
TDM = Time Delay Multiplier (delay in sec.)
V = fundamental RMS value of voltage (pu)
F = frequency of voltage signal (pu)
Pickup = volts-per-hertz pickup setpoint (pu)
The figure shows the volts/hertz inverse B curves.
5-290 L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL