ABB RELION 670 Series Technical Manual page 428

Section 7
Impedance protection
C
stat
ANSI11000008 V1 EN-US
Figure 225: High-resistance generator grounding with a neutral point resistor
There are some alternatives for connection of the neutral point resistor as shown in figure
(low voltage neutral point resistor connected via a DT).
422
R
fault
I
inj
a
+
R V
N inj
-
b
Z
Z
Measured
Û
R f
C
stat
V
N
Stator Reference
Impedance Z
1MRK 502 066-UUS B
Bare
Z
series I
inj
a
+
Z
R
V
mT
N
inj
-
b
Ref
ANSI11000008_1_en.vsd
226
Technical manual