AC flashover performance and polarization current of ethylene propylene rubber under different temperature

In order to evaluate the influence of AC flashover on the insulation performance of Ethylene Propylene Rubber (EPR) at different temperature, the characteristic indicators were studied, based on the polarization and depolarization current (PDC). In the paper, the partial discharge inception and extinction voltage and the flashover voltage were firstly measured under AC voltage at the ambient temperature and 90 °C, respectively. Before the occurrence of flashover, the partial discharge distribution was discussed under different voltage amplitude. Then, PDC was measured after the flashover test. The fit lines of PDC were drawn through the empirical formula for explaining the mechanism of AC flashover over the surface of EPR.