Study on the Influence of Test Methods on AC and DC Pollution Flashover Performance of Different UHV Insulators

This paper presents the flashover performance of three different insulators by using different test method. The results show that the influence of test method on the flashover performance of polluted insulators is significant. The average flashover voltage Uav obtained by even- raising the voltage method is 6.2% to 10.7% higher than the 50% breakdown voltage U50 obtained by the up-and-down method. The results also reveal a slight difference of pollution exponents obtained by different method which analyzed theoretically based on the Obenaus model.