Dielectric Strength Measurement for Different Materials during Dry Band Arcing and Flashover

Abstract

The polymer insulators are gaining significant importance and become primitive choice in high voltage power transmission system. However, due to organic nature of these insulators, aging and degradation seems to be significant under the polluted environment. The formation of pollution layer is one of the major causes of this degradation activity which causes the unequal field distribution around the insulator string. The aim of this paper is to comparatively analyze the dielectric strength during dry arcing band and flashover performance of silicon rubber with polyethylene, epoxy resin and EPDM based polymer insulators. For this purpose, these polymer insulators are modelled and simulated on COMSOL Multiphysics, a finite element-based software, and a uniform layer with 3mm thickness of solid water as pollution has been added on their surface. Then, their dielectric strength during dry bands arcing by creating the dry bands of 5 cm on different surface locations has been analyzed and compared. After that the dielectric strength during flashover, non-uniform or sharp edges of pollution layers are designed on the sheds of polymer insulators has been compared and analyze. The results show a promising trend in terms of quantifying the distribution of electric filed and can further be used as a base model to analyze them to do further investigation.