40.5 kV大电流固封极柱绝缘结构电场分析及优化设计  

Electric Field Analysis and Optimization Design of Insulation Structure for 40.5 kV Large Current Solid-insulation-embedded Pole

作　　者：李俊豪[1,2] 吴小钊 白维正 李长鹏 李猛 汤清双[1,2] LI Junhao;WU Xiaozhao;BAI Weizheng;LI Changpeng;LI Meng;TANG Qingshuang(XJ Group Corporation,Henan Xuchang 461000,China;Xuchang XJ-Driescher Wegberg Electric Co.,Ltd.,Henan Xuchang 461000,China)

机构地区：[1]许继集团有限公司,河南许昌461000 [2]许昌许继德理施尔电气有限公司,河南许昌461000

出　　处：《高压电器》2019年第7期87-92,共6页High Voltage Apparatus

摘　　要：大电流固封极柱必须大量采用软连接,容易造成局放超标及沿面放电,因而对其进行绝缘结构分析及优化设计件具有重要意义。文中运用有限元分析方法得出了40.5kV大电流固封极柱的电场分布云图,并提取分布较为集中的软连接及固定螺栓周围气体域的电场分布,指出软连接附近SF6气体中电场畸变,造成局放过大及沿面放电。依据复合绝缘电场理论,提出了在软连接周边固封极柱腔体内浇筑屏蔽网,并使屏蔽网与软连接等电位的优化方法。通过电场分析,优化后的软连接固定螺栓附近SF6气体电场强度由12kV/mm降低为7.5kV/mm,验证了优化设计方法理论上的可行性。局放试验结果表明,优化后的固封极柱局放量由203.98pC降低到2.37pC,雷电冲击试验峰值耐受电压由优化前的162kV提升到215kV,证明了提出的优化方案具备工程应用可行性,为大电流固封极柱结构设计及高压电器实际工程中气固复合绝缘电场的优化提供了有关参考。Large current solid-insulation-embedded poles must use soft connection. It causes partial discharge andsurface discharge. So it is of great significance for the analysis and optimization design of insulation structure. Theelectric field distribution of 40.5 kV embedded pole is obtained by using the finite element analysis method,and theelectric field concentration area’s distribution of the gas domain nearby bolts and soft connection is extracted. It is ob-vious that the electric field distortion of SF6 near soft connection,resulting in larger partial discharge and surface dis-charge. According to composite insulation electric field theory,an optimization method is proposed to cast shieldingnet around the soft connection in solid-insulation-embedded pole,and made shielding net and soft connection equi-potential. Through electric analysis,the maximum field strength of the SF6 gas near bolt decreased from 12 kV/mm to7.5 k V/mm,which confirmed the theoretical feasibility of the optimization design. Partial discharge tests show thatthe optimized embedded pole’s magnitude of partial discharge decreased from 203.98 pC to 2.37 pC. Peak withstandvoltage of lightning impulse test increased from162 kV to 215 kV,It confirmed the feasibility of the optimization mea-sures in engineering applications,which provided reference for optimization design of large-current solid-insulation-embedded pole and high voltage apparatus composite insulation electric field.

关 键 词：固封极柱 复合绝缘 局部放电 沿面放电 电场分析 绝缘试验 优化设计 

分 类 号：TM855[电气工程—高电压与绝缘技术]