Diagnostic techniques for the field evaluation of polymer concrete insulators

Several diagnostic techniques were employed in order to develop a methodology to evaluate the field performance of polymer concrete pin type insulators. These will be installed in the UK overhead distribution network under various weathering and pollution conditions. The techniques used include measurements such as surface roughness, water contact angle, surface resistance under clean fog conditions and flashover voltage under artificial pollution conditions. Results of these measurements are given for new and aged insulators. From the results, it is concluded that the evaluation methodology is a valuable tool for diagnosis of the effect of surface changes on the electrical performance of polymer concrete insulators.