A model for calculating the field distribution of polluted postinsulators during flashovers

摘要

A model has been developed for calculating the field distributionof polluted post insulators during flashover under AC voltage. The fielddistribution is calculated with an efficient finite-element method andverified by measurement. The effect of the field pattern on thepropagation of local arc is analyzed and a modified mechanism ofpollution flashover process is presented. This takes into account notonly the tangential electric field component but also the contributionof the normal field component to the flashover process. The potentialuse of the model for analyzing the pollution performance of otherhigh-voltage power equipment such as bushings, surge arresters, andcurrent transformers is discussed in the light of the results obtained