252 kV紧凑型GIL三相三支柱绝缘子绝缘结构设计与优化

Design and Optimization of Insulation Structure of Three-phase Tri-post Insulator in 252 kV Compact GIL

当GIL由单相运行转变为三相共箱时,滑动设计的支柱绝缘子绝缘结构将变得更为复杂,设计难度显著提高。为提升252 kV三相共箱式紧凑型GIL运行可靠性,应用有限元方法仿真分析了252 kV紧凑型GIL三相三支柱绝缘子电场分布特性,提取了电场设计指标值。将电场设计指标转化为去量纲化指标f,探讨了252 kV紧凑型GIL三相三支柱绝缘子f值随典型结构参数的变化规律,结合相对标准偏差分析得到了典型结构参数对各设计指标的影响程度。在此基础上,讨论了绝缘子的典型结构参数优化设计顺序与方法,给出了改进方案并分析了改善电极间电容分布以均匀金属件表面电场的方法。结果表明,改进方案的绝缘子表面合成场强、切向场强、嵌件表面场强分别降低了6.9%、11.1%、30.1%。改进方案使三相三支柱绝缘子的3个设计指标均满足了控制值要求,对252 kV紧凑型GIL中三相三支柱绝缘子的优化设计具有重要的指导与参考意义。

When GIL changes from single-phase operation to three-phase,the insulation structure of post insulator with sliding design will become more complex,and the difficulty in design will be significantly increased.In order to improve the operation reliability of 252 kV compact GIL,the electric field distribution characteristics of three-phase tri-post insulator were simulated and analyzed by using the finite element method.The design indexes of insulation structure were extracted and transformed into dimensionless index f.The variation law of f with typical structure parameters was discussed and the influence degree of typical structural parameters on design indexes was obtained by variation coefficient method.On this basis,this paper presented the optimization design sequence and the improvement scheme.In addition,the method of improving the capacitance distribution between electrodes to the surface field distribution of metal parts uniform was analyzed.The results show that the total and tangential field strength on insulator surface of the improved scheme are reduced by 6.9%and 11.1%,respectively.While on metal insert surface,the total filed strength is reduced by 30.1%.The usage of improved scheme ensures the design indexes to meet the requirements of the critical value,which has an important significance and reference for the design of three-phase tri-post insulator in 252 kV compact GIL.