COMPOSITE INSULATOR FLASHOVERS CAUSED BY BIRD DROPPING AND UNKNOWN REASONS

Based on the successful simulation of flashover caused by bird dropping, the mechanism of this kind of flashoverandtheflashoverconditions arestudied in this paper. It is found that the flashover caused by bird dropping is that the breakdown strength of the electric field of insulator at the air gap is suddenly changed where bird excrement drops, but not theflashoveralong theinsulator surface as previously assumed. Actually, inmanypreviouscasesof unknown reason flashover a considerable number could be attributed to bird droppings. The anti\|flashover method is also discussed.