Preliminary theoretical study on the flashover voltage of polymeric insulators

Presented in this paper are results of a flashover voltage study of polymeric insulating materials using a dynamic model. Since contamination performance of insulators depends both on the soluble (ESDD) and the non-soluble (NSDD) parts of air-borne contaminants deposited on the insulator surface and the nature of the surface, both ESDD/NSDD and surface resistance data have been used for this purpose. Use of surface resistance as an indicator of contamination severity is becoming popular, especially in the case of polymers, because the contaminant is encapsulated by the diffusion of polymeric chains from the bulk to the surface. Model results with good correlation to the experimental data have been obtained. Also reported are model results in close correlation with experimental observations that reflect the recovery characteristics of polymeric samples as a function of time and NSDD