Effect of shed configuration on DC flashover performance of ice-covered 110 kV composite insulators

Composite insulators have been used in power system for more than 20 years in China. Compared to porcelain and glass insulators, the pollution flashover performance of composite insulators is better, whereas the icing flashover performance is worse. Shed configuration is a key factor that influences flashover voltage of composite insulators covered ice or snow in icing regions. The DC flashover tests of artificially ice-covered 110 kV composite insulators with different shed configuration were carried out in the multi-function artificial climate chamber. The test results revealed that there are huge differences between the icing flashover voltages of the composite insulators with different shed configuration. The test results indicate that icing flashover performance of the improved composite insulators for icing regions is not always superior to that of the standard composite insulators.