Effect of pollution severity and dry band location on the flashover characteristics of silicone rubber surfaces

This paper investigates the flashover and ageing behavior of silicone rubber insulators under various contamination and dry band conditions. Effect of pollution severity, leakage distance and dry band location on the flashover characteristics of silicone rubber insulator was investigated. Flashover voltage and electric field distribution were measured under different pollution severity levels and dry band conditions. Effect of leakage distance on flashover voltage was also studied. Tests were carried out in a climate chamber and specific values of humidity and ambient temperature were used. A commercially available simulation package, COMSOL Multiphysics, was used to validate the experimental results. Electric field and potential along a silicone rubber sample were studied under different pollution severity and dry band conditions. Fourier transform infrared spectroscopy was used to analyze the chemical changes on the insulator surface and investigate the hydrophobicity recovery property of silicone rubber after flashover tests. The results of this study will further our knowledge regarding the flashover of silicone rubber outdoor insulators under contaminated and dry band conditions and could be used to improve the existing flashover models.