GE P645

You can use PSL to combine the stages to create a multi-stage V/Hz trip operating characteristic, as shown below:
Not
e:
Consult the manufacturers’ withstand characteristics before formulating these settings.
V00865
V
/
H
z
(
%
)
V/Hz(%)
Multi-
Characteristic
V/Hz>2
V/Hz>3
V/Hz>4
V/Hz>1
Figure 120: Multi-stage overfluxing characteristic
V/Hz>2 = 1.4 p.u.
t = 1 s
V/Hz>3 = 1.2 p.u.
t = 4 s
V/Hz>4 = 1.1 p.u.
t = 0 s
V/Hz>2 Trip
V/Hz>3 Trip
V/Hz>3 Start
V/Hz>4 Start
V/Hz>1 Inhibit
1
V/Hz>1 = 1.06
TMS = 0.08
V/Hz>1 Trip
R14 V/Hz Trip
1
E00866
Figure 121: Scheme logic for multi-stage overfluxing characteristic
Chapter 12 - Frequency Protection Functions P64x
258 P64x-TM-EN-1.3