Discharge behavior and dielectric performance of artificially polluted hydrophobic silicone rubber

Flashover voltage and discharges behavior were investigated with silicone rubber (SiR) polluted with fog, red clay or carbon particles. For a SiR polluted with carbon, partial discharges occur between water droplets and form interspersed dry bands. For a SiR polluted with red clay, the leakage current induces uniform dry bands and dry-band arc discharges. Because flashover occurs through the dry bands, the noticeable difference in flashover voltage between the polluting materials is not seen. The pollution deposit changes the surface state and causes partial discharges which lead large leakage current, however, the partial discharges don't significantly lower insulation performance.