±200 kV直流盆式绝缘子的研制

Development of ±200 kV DC Basin Insulator

盆式绝缘子是气体绝缘金属封闭输电线路(GIL)设备研制的核心元件,直流电压下绝缘子长期承受单极性直流电场作用,其表面会积聚大量电荷,导致固-气界面处局部电场畸变,极易引发绝缘子沿面闪络,降低设备的绝缘水平。本研究借鉴直流绝缘子的相关研究成果,通过合理控制绝缘子表面场强及提高绝缘材料的电阻率实现对表面电荷积聚的抑制,借助仿真手段指导结构优化设计,完成了绝缘子浇注并通过交直流应力下的介电试验及力学性能试验,验证了设计的正确性。

Basin insulator is the core component of gas insulated metal transmission line(GIL)equipment.A large amount of charge will accumulate on the surface of insulators under long-term effect of unipolar DC electric field,resulting in the electric field distortion at the solid-gas interface,which leads to surface flashover of insulators easily and reduces the insulation performance of equipment.On the basis of relevant research results of DC insulators,this study restrains the accumulation of surface charges by reasonably controlling the surface field strength of insulators and increasing the resistivity of insulating materials.The structure design was optimized by simulation methods,and the insulator was prepared by casting,then dielectric tests and mechanical performance tests under AC and DC stress was carried out and passed,which verified the correctness of design.