GE T60

5-268 T60 Transformer Protection System GE Multilin
5.6 GROUPED ELEMENTS 5 SETTINGS
5
INVERSE CURVE C:
The curve for the Volts/Hertz Inverse Curve C shape is derived from the formula:
(EQ 5.47)
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 volts/hertz inverse C curves are shown below.
Figure 5–134: VOLTS-PER-HERTZ CURVES, INVERSE CURVE C
T
TDM
V
F
--- -


Pickup
0.5
1–
-----------------------------------------------------
when
V
F
--- -
Pickup=
Time to trip ( in seconds)
Multiples of volts per hertz pickup
830740A1.CDR
Time
delay
setting