Koeppl, G.; Braun, D.
ABB; KOEPL
1-phase faults in generator stator windings are predominantly intermittent arcing faults, as may be deduced from MV cable tests. Simulations show that energy absorption in the fault resistance at intermittent faults is about 20 times higher than for a persistent "textbook" fault. Resonant grounding of the generator neutral prolongs substantially the intervals between re-strikes thus reducing correspondingly arc damages in the stator iron. Hence resonant grounding of the generator neutral is to be preferred to high ohmic resistive grounding.
