Effects of Surface Treatment on the Flashover Characteristics of the GIL Tri-post Insulators

Because of its excellent insulation, thermal and mechanical properties, anhydride cured bisphenol-A epoxy resin is widely used in the support, insulation and packaging of electrical equipment and other key components. Surface defects of various sizes and orientations can occur on the tri-post insulator surface during molding due to clamping lines, die wear, and impurities. So, polishing is essential to remove these irregularities and foreign matters. This paper examines the influence of surface treatment on the flashover characteristics of gas-insulated metal-enclosed lines (GIL) tri-post insulators. The results indicate that the presence of metal dust, even in small quantities, significantly reduces the flashover voltage of the insulators regardless of the surface polishing, highlighting the detrimental effect of environmental contaminants on insulating performance.