Simulation Analysis of Electric Field and Mechanical Stress of Ceramic Supporting Insulator in UHVDC Wall Bushing

Compared with epoxy resin composite materials, silicon nitride ceramics have excellent insulation and mechanical properties, and have certain application potential in SF6 gasinsulated UHVDC equipment. Based on the silicon nitride ceramic material, this paper designs a "wine bottle shape" insulating pillar suitable for ±800kV pure SF6 gas-insulated wall bushing. And using finite element simulation to compare its electrical and mechanical properties with traditional epoxy resin pillars. The study found that: compared with epoxy resin insulated pillars, the peak values of the tangential and normal electric fields of the ceramic insulating pillars are lower by 15% and 23.6%, respectively; The safety margin of ceramic insulated pillars is 112% higher than that of epoxy pillars under operating conditions; Under the magnitude 8 earthquake intensity, the safety margin of ceramic insulated pillars is 21.25% higher than that of epoxy pillars. The silicon nitride ceramic insulation pillar designed in this paper has passed the type test and has been put into operation at the Wuhan Converter Station in China.