Contamination accumulation and withstand voltage characteristics of various types of insulators

Service experience has shown that contamination degrees of insulators may be different from one type to another depending on the shed profile and the insulation material even under the same service conditions. As a countermeasure against contamination flashover, the 3-outer-rib type insulator featuring open profile has proved superior contamination accumulation performance in the industrial contamination area. In this study, an artificial contamination test called Dust Cycle Method (DCM) was conducted to evaluate the anti-contamination performance of various types of insulators. The test results indicated that insulators with open profile collect much less contaminants compared to the conventional Fog type insulators with under-ribs, showing good agreement with the field test results of 500 kV AC transmission line in East China region, in terms of both contamination degree and surface contamination distribution.