Various artificial contamination withstand voltage test methods and a comparison of their results on polymer and porcelain insulators

Polymer insulators are considered to have higher withstand voltages under contamination conditions due to hydrophobicity on the surface compared with conventional ceramic insulators. This is based on a part of artificial contamination test results and field experiences. However, international standards of artificial contamination withstand voltage test for polymer insulators have not yet been established. Now, it is under discussion at some international conferences, such as CIGRE, IEEE and various other research organizations. Artificial contamination withstand voltage tests normally used for ceramic insulators, and some other tests simulating the different wetting conditions, were carried out on a silicone rubber polymer insulator and a porcelain long-rod insulator for comparison purposes. This paper describes these test results and the influence of the test methods on the contamination withstand voltage.