Influence of air-gap characteristics on the icing flashover performance for the plate model of composite insulators

The air-gaps will appear in the ice-layer during icing and ice-melting process of composite insulators. The icing flashover process and flashover voltage are obviously affected by the air-gaps. In order to research the influence of the air-gaps on the icing flashover performance of composite insulators, the icing flashover tests were carried out by using the plate model of insulators. The influence of different characteristics of the air-gaps on the flashover performance of the model, such as the length, position, number and angle of model was researched, and the flashover process, variation of the leakage current and flashover voltage under different kinds of air-gaps were also compared. The results show that, the development path of the arc changes with the different characteristics of the air-gaps. The flashover voltage decreases at first and then increases with the increasing of the length and model angel of the air-gaps. The flashover voltage increases when the distance between the air-gap and the electrode becomes larger, and the increasing of the air-gap number can also increase the flashover voltage with the constant whole length of the air-gaps.