ABB REG670 - Page 419

fundamental frequency voltage component. It has an excellent rejection of the third
harmonic voltage component commonly present in such generator installations.
G
Generator
Circuit
Breaker
ROV2 PTOV
59N 3Uo>
ROV2 PTOV
59N Uo>
ROV2 PTOV
59N 3Uo>
Unit
transformer
LV side VT
Generator
terminal VT
Generator
29MVA
11kV
150rpm
Earthing
resistor and
neutral point
VT
Unit
Transformer
29MVA
121/11kV
YNd5
110kV Bus
#3
#2
#1
11 0.11
/
3
3
kV
11 0.11
/
3 3
kV
11
/ 0.11
3
kV
1000Ω
IEC10000171-2-en.vsd
IED
IEC10000171 V2 EN
Figure 205: Voltage-based stator earth-fault protection
ROV2PTOV application #1
ROV2PTOV is here connected to a voltage (or distribution) transformer located at
generator star point.
1. Due to such connection, ROV2PTOV measures the Uo voltage at the generator
star point. Due to such connection, ROV2PTOV measures the Uo voltage at the
generator star point. The maximum Uo voltage is present for a single phase-to-
earth fault at the generator HV terminal and it has the maximum primary value:
1MRK 502 071-UEN - Section 10
Voltage protection
Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062 413
Application manual