ABB REG670 Applications Manual page 299

1MRK 502 071-UEN -
Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
Application manual
Uinj
7
I
U
REX060/ RIM module
REG670
Generator Protection Panel
IEC11000014 V1 EN
Figure 155: Connection of REX060 for rotor earth fault protection
1 Generator unit consisting of a synchronous generator and a step-up transformer
2 Generator field winding
3 Capacitor coupling unit which is used to provide insulation barrier between rotor circuit and injection
equipment
4 Cable used to inject the square-wave signal into the rotor circuit
5 Connection for measurement of injected current. This signal is amplified in REX060 before it is
passed on to IED for evaluation.
6 Connection for measurement of injected voltage. This signal is amplified in REX060 before it is
passed on to IED for evaluation.
7 Two VT inputs into IED which are used to measure injected current and voltage
8 Protection for excessive over-voltages posed by generator. REX060 can withstand without damage
maximum voltage of 120V and when used together with REX062 up to 240V.
The measured impedance Z
= ´ +
Z K Z
measured 1 bare
GUID-20ADF3F6-6A89-4B5F-B0DA-9740C4FD5482 V2 EN
Where:
U
=
Inj
Z
bare
I
Inj
IECEQUATION17021 V1 EN
8
U>
Rshunt
5
6
is calculated by the complex equation:
Measured
K
2
Section 8
Impedance protection
4
3
R C
REX061
2
IEC11000014-4-en.vsd
Step-up
Transformer
1
~
Generator
R
N
293