Electrical Treeing Degradation Characteristics of Glass Fibre Reinforced Epoxy Composites Under Extension-Compression Mechanical Loads

Insulated pull rod is a key component of gasinsulated switchgear for opening and closing operations. Insulated rod is subjected to high electric field and mechanical load during operation, and its performance directly influences the stability of power system operation. In this paper, the electrical tree branch degradation process of GFRP composites under electric field superimposed tensile-compressive dynamic loading is investigated by experiment and simulation. The tensile-compressive dynamic loading accelerates the degradation of electric branches more than the single tensile loading. In detail, the electric tree growth rate of GFRP under dynamic loading was significantly enhanced and the average breakdown time was reduced. The simulation results show that the stress distribution at the interface of fiber and epoxy resin under dynamic loading is more concentrated, which is more likely to initiate defects. The research can provide a new method for testing the performance of insulated pull rods.