Section 4
1MAC309294-MB F
Protection functions
146
RER620
Technical Manual
Figure 62:
Ground-fault situation in an isolated network
Directional ground-fault protection in a compensated network
In compensated networks, the capacitive fault current and the inductive resonance coil
current compensate each other. The protection cannot be based on the reactive current
measurement, since the current of the compensation coil would disturb the operation of the
relays. In this case, the selectivity is based on the measurement of the active current
component. The magnitude of this component is often small and must be increased by
means of a parallel resistor in the compensation equipment. When measuring the resistive
part of the zero sequence current, the relay characteristic angle (RCA) should be set to 0
degrees and the operation criteria to I
0
cos(φ) or phase angle.The figure below describes
how ground fault current is defined in compensated neutral networks.
A
B
C
C
0
-
ΣI
01
ΣI
02
-
ΣI
02
I
ef
R
0
0
V
0
V
0
V
Содержание RER620
Страница 1: ...Relion Protection and Control Advanced Recloser Protection and Control RER620 Technical Manual ...
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Страница 22: ...Section 1MAC309294 MB F 16 RER620 Technical Manual ...
Страница 88: ...Section 3 1MAC309294 MB F Basic functions 82 RER620 Technical Manual ...
Страница 278: ...Section 4 1MAC309294 MB F Protection functions 272 RER620 Technical Manual ...
Страница 362: ...Section 5 1MAC309294 MB F Control functions 356 RER620 Technical Manual ...
Страница 418: ...Section 7 1MAC309294 MB F Measurement functions 412 RER620 Technical Manual ...
Страница 428: ...Section 8 1MAC309294 MB F Recording functions 422 RER620 Technical Manual ...
Страница 464: ...Section 9 1MAC309294 MB F Other functions 458 RER620 Technical Manual ...
Страница 554: ...Section 10 1MAC309294 MB F General function block features 548 RER620 Technical Manual ...
Страница 568: ...Section 12 1MAC309294 MB F Relay physical connections 562 RER620 Technical Manual ...
Страница 574: ...Section 13 1MAC309294 MB F Technical data 568 RER620 Technical Manual ...
Страница 576: ...Section 14 1MAC309294 MB F Relay and functionality tests 570 RER620 Technical Manual ...
Страница 578: ...Section 15 1MAC309294 MB F Applicable standards and regulations 572 RER620 Technical Manual ...
Страница 582: ...Section 16 1MAC309294 MB F Glossary 576 RER620 Technical Manual ...
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