ABB RELION 670 Series Technical Manual page 422

Section 7
Impedance protection
7
9
95 % SEF
REG670
ANSI11000067 V1 EN-US
Figure 222: Example installation for stator injection
1 Generator unit consisting of a synchronous generator and a step-up transformer
2 Grounding resistor for the stator winding
3 Neutral point VT which is used as injection point and also to provide galvanic separation between primary
circuit and injection equipment
4 Cable used to inject the square-wave signal into the stator circuit
5 Connection for measurement of injected current. This signal is amplified in REX060 before it is given to
REG670 for evaluation.
6 Cable for measurement of injected voltage at the injection point. This signal is amplified in REX060 before it
is given to REG670 for evaluation.
7 Two VT inputs into REG670 which are used to measure injected current and voltage
8 Cable for 95% stator earth-fault protection
9 Separate VT input in REG670 used for 95% stator earth-fault protection
10 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.
416
10
U>
Vinj
Rshunt
I
V
REX060/SIM module
Generator Protection Panel
4
5
6
8
ANSI11000067-1-en.vsd
1MRK 502 066-UUS B
Step-up
Transformer
1
GEN
Generator
R
N
2
3
Technical manual