Flashover of insulators in a wet environment

This paper describes a method based on electric field calculation and random walk theory for evaluating insulator performance in a wet environment. Arc bridging of sheds via water particles suspended in close proximity to the insulator has been considered. The role of insulator dimensions (shank diameter, shed diameter and number of sheds) on the flashover performance has been discussed. It is shown that the increased probability of flashover due to the presence of water particles when compared to insulators with only wet surfaces can be quantified. With low to moderate levels of contamination commonly encountered in service, the relative increase in flashover probability is higher due to the presence of suspended water particles than that obtained under heavy contamination.