Pollution Performance of RTV Coated Insulators

Abstract

Theincrease in power demand necessitates the usage of EHV and UHV transmission system. The growth of industries causes higher pollution level in the ambient condition on insulators. This increases the pollution severity of the site which results in pollution accumulation on the surface of Insulators. This causes flashover across insulator. Flashover across polluted insulators poses a serious threat to the reliability of the system and leads to system outages. There are many remedial measures to minimize the flashover of a porcelain insulator under pollution conditions. One such method is the application of hydrophobic coatings such as Room Temperature Vulcanizing Silicone Rubber on the surface of ceramic insulators. Laboratory testing of coated insulators has been carried out based on the solid layer method and by the inclined plane tests at constant voltage to evaluate the RTV coatings withstands capability against tracking and erosion. The performance of the coatings was assessed by monitoring the leakage current on the insulator surfaces. The applied voltage and leakage current were monitored throughout the tests. In order to optimize and economize the usage of RTV coatings various tests were performed and results are analyzed. It was possible to conclude from the test results that one fourth length of RTV coating is sufficient to withstand the pollution severity.