E-Field Simulation and Voltage Withstand Test Analysis of Solid Insulators for AC GIS Used in High-Speed Railway Traction Substation

Abstract

The solid insulators are widely used in alternating current gas-insulated switchgear (GIS) equipment in high-speed railway traction substation. They have both mechanical support and electrical insulation functions. AC withstand voltage test is required before they are put into operation. In this paper, the series resonant circuit is theoretically analyzed, and the transient voltage change process of GIS solid insulators during sudden flashover is simulated and analyzed in the MATLAB/Simulink computing environment. The 3D electric field simulation of basin insulators and typical solid insulators with insulation support is carried out by using ANSYS electric field simulation platform. The withstand voltage test of the real interval of GIS is carried out to obtain the opening of circuit breaker. The relationship curves between Q, I and applied voltage U of solid insulator under two operating conditions are obtained. The results show that after flashover of solid insulators in series resonant circuit, the arc will be extinguished immediately after high voltage drop, and the recovery voltage will be established for a long time. The typical electric field distribution of solid insulators has concentrated area of local electric field, and flashover in field withstand voltage test starts in high field strength area. The research results of this paper provide some theoretical support for the field voltage withstand test of solid insulators used in AC GIS with series resonant circuit.