GIS变电站进线电缆雷电过电压影响因素分析  

Analysis on Influence Factors of Lightning Overvoltage at the GIS Substation Entrance Cable

作　　者：何哲 朱斌 梁晖 汪璐悦 HE Zhe;ZHU Bin;LIANG Hui;WANG Luyue(NARI Group Corporation（State Grid Electric Power Research Institute）Co.,Ltd.,Nanjing 211106,China)

机构地区：[1]南瑞集团(国网电力科学研究院)有限公司,南京211106

出　　处：《电瓷避雷器》2018年第5期84-88,共5页Insulators and Surge Arresters

摘　　要：架空线路转接电缆方式广泛应用于GIS变电站建设,必须分析GIS变电站进线电缆雷电过电压影响因素以合理防护。利用EMTP软件搭建220 kV GIS变电站模型,计算线路发生雷电反击情况下变电站进线电缆侵入波过电压,分析不同电缆接地方式和避雷器安装方式下的防护效果,最后讨论进线电缆长度、线芯导电率和绝缘材料相对介电常数等参数对电缆过电压的影响。仿真结果表明:线路发生反击时,电缆侵入波过电压波形存在较为明显的振荡,且末端过电压高于首端。电缆采取两端接地方式情况下末端过电压最小,过电压随着接地电阻的增大而增加,但过电压增加幅度不明显。安装避雷器能够有效抑制电缆侵入波过电压,首末两端均安装避雷器防护效果最佳。电缆末端侵入波过电压随着电缆长度的增加而降低,随着线芯电阻率的增大而降低。电缆绝缘材料相对介电常数越大,末端侵入波过电压越小。Overhead line conversion cable has been widely used in the construction of GIS substation,so it is necessary to analyze influence factors of lightning invaded wave overvoltage at the entrance cable.Equivalent model of 220 kV GIS substation was established in ATP-EMTP to calculate lightning overvoltage in case of counteracting. Protection effects of different grounding modes and installation method of arresters were discussed. Finally,influence of length of the cable,resistivity of the core material and insulator material outside the corewere analyzed. Results show that： lightning invaded wave overvoltages show apparent oscillation and the overvoltage at the cable terminal is higher than that of the head. The minimum lightning overvoltage presents when screen of the cable connects to earth at both ends and the overvoltage increase with the increasing of grounding resistance slightly. Installing arresters on the both ends can provide best insulation protection. Overvoltage at the cable terminal decreases with the length of cable as well as the increasing of resistivity of the core material. Overvoltage is also reduced when increasing the relative permittivity ofthe insulator material outside the core.

关 键 词：GIS变电站 进线电缆 雷电过电压 影响因素 避雷器 

分 类 号：TM863[电气工程—高电压与绝缘技术]