DC flashover performance of iced insulators under pressure and pollution conditions

In an artificial climate chamber, DC flashover tests of insulator strings were performed under various ice, pressure, and pollution conditions. Based on these results, curves for the relationship between the DC flashover voltage of the insulator string and the pressure, the ice weight, and the pollution degree are given and analyzed. It is shown that, under the same ice weight and the same pressure, the DC flashover voltage of the precontaminated iced insulators is lower than that of clean insulators. The larger the pollution degree, the lower is the flashover voltage. Under the same pollution degree and the same pressure, the DC flashover voltage of the precontaminated iced insulators decreases as the atmospheric pressure decreases