Performance of HVDC Insulators under Contaminated Conditions

A review is presented on the performance of outdoor HVDC insulators in a polluting environment. Results from several recent studies have been included. Physical conditions and processes that lead to electrical breakdown are delineated. Both field and laboratory test results are presented to demonstrate the effects of ambient weather conditions and the contamination process on the flashover characteristics of an insulator. In particular, recent field test data from the Pacific HVDC Intertie has been included. Particle deposition mechanisms under the influence of electric field are also summarized. Lastly, leading theories pertaining to this field are reviewed.