Study on Pollution Flashover Characteristics of ±800kV DC Composite Insulators

This paper presents the basic structure parameters of 800kV DC composite insulator specimen and the pollution test scheme. The condition of 800kV DC composite insulator pollution test under whole 800kV voltage and whole structure dimension completed in STRI, which is completed first time in the world, is introduced. The study results indicate that the linear relation between the pollution flashover voltage and the length of 800kV DC composite insulator is high-blooded. The consistency of test data between STRI and China lab is good. The pollution flashover characteristics of I string and V string under whole voltage and whole structure dimension is confirmed. The formula of DC pollution flashover grads calculated by SDD of DC composite insulator is obtained.