AC Flashover Performance of 10 kV Rod-Plane Air-Gapped Arresters under Rain Conditions

Abstract

According to operational experience of power systems, the outdoor insulation strength can be reduced due to the effect of rain. Till now, little work has been done to investigate the flashover performance of air gapped arresters under rain conditions. Therefore, in this paper, experiments were carried out and the AC flashover performance of 10 kV arresters with different air gap structures was studied. The experimental results show that, for the tested arresters, the flashover current mainly flows through the air gaps and zinc oxide varistors under rain conditions. It is also confirmed that the flashover voltages decrease with the increasing of rain intensity and conductivity. In the windward direction, the wind can distort the water streams between the air gaps and rise the flashover voltages. In the leeward direction, if the rod electrode is beyond the range of the plane electrode, the flashover voltage researches the smallest value when the wind speed is 4 m/s. Analysis and discussions have been done to explain the experimental results, and the research in this paper may provide reference to improve the flashover performance of air gapped arresters under rain conditions.

Keywords

• air gapped arresters
• air gap
• rain
• wind
• flashover