Effects of UV Radiation and Contaminant on The Properties of Polymeric Insulator

The frequency of ceramic insulator failures is relatively high, especially in severely polluted areas. Due to superiority in repelling contaminated pollution, polymeric insulators are set to replace ceramic insulators. This research investigated the effects of aging due to ultraviolet radiation, humidity, and contaminant of the polymeric insulators for virgin and aged samples. The applied condition for the samples consist of clean fog without kaolin, clean fog with kaolin, salt fog without kaolin, and salt fog with kaolin, according to IEC 60507. In this research, some samples were put in a chamber and exposed to ultraviolet radiation by UV lamps, and penetrated in a contaminant solution vessel according to ANSI C-29 13-2000. The electrical properties and changes on the surface were investigated by measuring leakage current and total harmonic distortion (THD). Thermal Resistance of samples was investigated by using TG/DTA analysis. The hydrophobicity class of virgin and aging samples was investigated by measuring contact angle based on IEC 62073:2016. Surface morphological degradation and material composition were assessed by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX). Experimental results concluded that aging and contaminant significantly affect the aging of the insulators. Due to the pollutant contamination, the surface has a rougher texture, resulting in reduced hydrophobicity ability. The reduction causes conductive currents to flow over the insulators' surface. Due to the aging process, silicone content decreases, but oxygen and carbon increase. Increasing oxygen is caused by oxidation due to UV radiation and corona activity.