Tracking resistance by the RWDT and flashover characteristics of polymeric materials of outdoor HV insulator

This paper describes the results of a study on the tracking performance of high voltage polymeric insulating materials based on the rotating wheel dip test (RWDT). The influence of surface degradation was evaluated through measurement of the flashover performance after and before tracking test. It is concluded that the surface degradations of polymeric insulating materials are directly related to the partial discharge and weight loss. Leakage current on the surface of specimens is useful in evaluating degradation aspects. In the RWDT, the breakdown specimen is not affected by the dry flashover voltage, despite the fact the that the surface degradation of tracking test has different state on each specimen