ABB RED650 Applications Manual

1. IdMin
2. EndSection1
3. EndSection2
4. SlopeSection2
5. SlopeSection3
Section 1
UnrestrainedLimit
Section 2
Section 3
Restrain
Operate
unconditionally
5
4
3
2
1
0
0 1 2 3 4 5
IdMin
EndSection1
EndSection2
Restrain current
[ in pu of IBase]
Operate current
[ in pu of IBase]
SlopeSection2
SlopeSection3
en05000300.vsd
Operate
conditionally
IdMinHigh
A
C
B
IEC05000300 V1 EN-US
Figure 39: Restrained differential function characteristic (reset ratio 0.95)
where:
100%
Ioperate
slope
Irestrain
D
=
D
×
EQUATION1246 V1 EN-US
Line differential protection is phase-segregated where the operate current is the
vector sum of all measured currents taken separately for each phase. The restrain
current, on the other hand, is considered as the greatest phase current in any line
end and it is common for all three phases.
IdMin
M12541-121 v6
This setting is a multiple of IBase and must take into account the fundamental
frequency line charging current, and whether a power transformer is included in the
protected zone or not.
Section 6 1MRK 505 393-UEN B
Differential protection
88 Line differential protection RED650 2.2 IEC
Application manual

ABB RED650 Specifications

General

Brand	ABB
Model	RED650
Category	Protection Device
Language	English