Study On The Icing Flashover Characteristics Of 500kV AC Post Insulators

Insulator icing is a special form of contamination,the insulation performance of insulators will decrease significantly when under the combined conditions of ice-covering, pollution and high altitudes。In order to analyze the icing flashover characteristics of post insulators,the icing flashover characteristics of energized 500 kV post insulators are studied in this paper in a large-scale artificial climate chamber at ultra high voltage (UHV)AC test base of SGCC. The state of icing, the discharge process of 500 kV post insulators and influence of pollution are discussed. The state of icing of 500 kV post insulators between the one with increase climbing skirts and the one without increase climbing skirts is discussed too.The discharge process and flashover voltages of 500 kV post insulators with increase climbing skirts are discussed preliminarily. And the test results carry out a preliminary verification and research useing the multi-arc circuit model.The research results can be a reference for the post insulators icing flashover characteristics tests and external insulation coordination of transformer substation in the heavy icing regions of China.