Study on Local Arc development and Influencing Factors of Insulator Pollution Flashover

The surface of outdoor running insulator is easy to form conductive dirt layer because of exposing to heavy polluted atmospheres for long time. Heat effect produced by leakage current causes the surface to form a dry band where flashover happens and produces local arc even at a low voltage. The local arc develops to the whole surface of the insulator and causes power system accidents. The formation time of local arc is short and the developing speed is fast. The internal microscopic particles of the local arc collide frequently which determines the pollution flashover voltage. A microscopic local arc model of insulator pollution flashover is established in this paper based on FZSW10/4 pillar composite insulator. The effects of the formation process of the local arc, the salt density of the pollution layer and the temperature on the micro parameters of the flashover local arc are simulated based on the artificial contamination experiment. The result shows the micro physical reason why the salt density of the pollution layer, the temperature and the length of the dry band have effects on the parameters of the local arc sheath and the arc column region. The study has a theoretical reference for using favourable means to limit the local flashover of composite insulators and improving the pollution flashover voltage.