Investigation on Flashover Voltage and Non-uniform Pollution Correction Coefficient of DC Composite Insulator

Non-uniform distribution on an insulator has a great influence on the DC pollution flashover voltage. a lot of investigations have been carried out on the non-uniform pollution flashover performance of the porcelain and glass insulators, but the research on the composite insulators is still very few. In this paper, based on the artificial pollution tests carried on the DC composite insulator, the influence of non-uniform pollution distribution of the DC composite insulator on the flashover performance is analyzed, and the correction formula of the non-uniform pollution flashover voltage is proposed. The test results show that, the correction formula indicating the influence of non-uniform pollution distribution on the flashover voltage could be expressed as K=1-b×log(T/B). For the tested composite insulator, the factor b is 0.141~0.156, which is smaller than those of porcelain and glass insulators.