CYG PRS-7367 - Page 225

Protection Functions
PRS-7367 217
12
-
2
r
II
I 
fundamental frequency components on the phase and neutral sides of the current.
Assuming that the positive direction of the current is towards the machine.
12
kk,
1
k
is Slope section 2, the typical setting is 0.6.
2
k
is Slope section 3, Optional, the default value is 1 when not configured. If
1
k
=
2
k
，
there are two operation sections.
12rr
II，
1r
I
is the biased current of End section 1;
2r
I
is the biased current of End section 2;
dl
I
dl
I
is the Biased low operate value, it is equal to Low operate value * Machine_Ie
Ir
Id
Idl
Idh
k2
k1
o
Ir1 Ir2>Ir1
Section1
Section2
NON
OPERATE
INST
OPERATE
DIFF
OPERATE
k1=k2
Figure 3.46-4 Differential protection action characteristic curve (two sections)