ABB Relion 670 Series Technical Reference Manual page 135

1MRK505222-UUS C
Technical reference manual
Operate current
[ in pu of IBase]
5
4
3
A
2
Section 1
1
IdMin
0
0
EndSection1
IEC05000300 V1 EN
Figure 52: Description of the restrained-, and the unrestrained operate
characteristics
where:
D
Ioperate
= ×
slope
100%
D
Irestrain
EQUATION1246 V1 EN
and where the restrained characteristic is defined by
the settings:
1. IdMin
2. EndSection1
3. EndSection2
SlopeSection2
4.
5. SlopeSection3
Operate
unconditionally
UnrestrainedLimit
Operate
conditionally
Section 2
SlopeSection2
1 2 3
EndSection2
Section 5
Differential protection
IdMinHigh
C
B
Section 3
SlopeSection3
Restrain
4 5
Restrain current
[ in pu of IBase]
en05000300.vsd
129