Damage Threshold of Polymeric Housing Materials Used for Outdoor HV Insulators

Abstract

A laser irradiation technique has been used to determine the threshold energy for degradation in silicone rubber, ethylene propylene diene monomer and epoxy materials. Silicone rubber exhibited an impulsive or step degradation behavior while ethylene propylene diene monomer and epoxy samples indicated an exponential trend. The temperatures required to initiate degradation in these samples were calculated from laser photo-thermal models and the results were found to be in good agreement with the experimental values obtained from thermogravimetric analysis.