ABB REG670 - Connection Examples for High Impedance Differential Protection

7.2.3 Connection examples for high impedance differential
protection
WARNING! USE EXTREME CAUTION! Dangerously high
voltages might be present on this equipment, especially on the plate
with resistors. De-energize the primary object protected with this
equipment before connecting or disconnecting wiring or performing
any maintenance. The plate with resistors should be provided with a
protective cover, mounted in a separate box or in a locked cubicle.
National law and standards shall be followed.
7.2.3.1 Connections for three-phase high impedance differential protection
Generator, reactor or busbar differential protection is a typical application for three-
phase high impedance differential protection. Typical CT connections for three-phase
high impedance differential protection scheme are shown in figure 61.
L1
(A)
L2
(B)
L3
(C)
Protected Object
CT 1200/1
Star/Wye
Connected
L1
(A)
L2
(B)
L3
(C)
CT 1200/1
Star/Wye
Connected
7
8
9
1
0
1
1
1
2
1
2
3
4
5
6
AI01
(I)
AI02
(I)
AI03
(I)
AI04
(I)
AI05
(I)
AI06
(I)
7
6
X1
R4 R5 R6
1
2
1
2
1
2
11 12 13 14
U U U
R1
1
3
4
2
1
3
R2
2
4
1
3
R3
2
4
1 2 3 4 5 6 7
L1 (A)
L2 (B)
L3 (C)
N
3-Ph Plate with Metrosils and Resistors
2
3
5
4
X X
L1 (A)
L2 (B)
L3 (C)
N
1
IED
IEC07000193-5-en.vsdx
SMAI2
BLOCK
REVROT
^GRP2L1
^GRP2L2
^GRP2L3
^GRP2N
G2AI3P
G2AI1
G2AI2
G2AI3
G2AI4
G2N
IEC07000193 V5 EN
Figure 61: CT connections for high impedance differential protection
Section 7 1MRK 502 071-UEN -
Differential protection
156 Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
Application manual