气体绝缘开关柜支柱绝缘子电场分析及优化设计

Electric Field Analysis and Structure Optimization of Post Insulator in Gas Insulated Switchgear

为解决气体绝缘开关柜内支柱绝缘子沿面闪络及局部放电问题,文中基于12 kV干燥空气绝缘开关柜内的支柱绝缘子开展研究。支柱绝缘子优化前的外绝缘特性分析结果表明,绝缘子表面、楔形气隙及金属嵌件表面场强严重集中。本研究通过参数化建模及扫描计算对支柱绝缘子进行优化设计,并基于优化后的方案进行电场分析,支柱绝缘子关键部位场强可降低40%以上,该优化措施可同时避免引起其他部位的电场升高,在保证绝缘子小型化的同时,使得支柱绝缘子的绝缘性能得到大幅提升。优化后,试制样机通过绝缘试验的验证。

To solve the surface flashover and partial discharge problem of post insulator in the switchgear,research is carried out based on the post insulator in 12 kV dry-air insulated switchgear.The results of analysis on external insulation characteristics of post insulator show that,the electric field of post insulator surface,cuneate airgap and metal insert surface is extremely concentrated.The optimization design is done by parametric modeling and scanning calculation and the electric field is analyzed based on the optimized scheme.The electric field strength of the critical parts can reduce more than 40%.Besides,this scheme can avoid the electric field increase of other parts of the post insulator and the insulation characteristics can be improved significantly while keeping the post insulator miniaturization.At last,the optimized prototype has passed the insulation test verification.