基于PSCAD/EMTDC的高压电缆护套沿线过电压计算分析  

Calculation and Analysis of Overvoltage Along Line of High-Voltage Cable Sheath Based on PSCAD/EMTDC

作　　者：叶昊亮 杨勇 曹俊平 王少华 何坚 林浩凡 张帅 YE Hao-liang;YANG Yong;CAO Jun-ping;WANG Shao-hua;HE Jian;LIN Hao-fan;ZHANG Shuai(State Grid Zhejiang Electric Power Research Institute,Hangzhou 310014,China;Hangzhou Yineng Electric Power Technology Co.,Ltd,Hangzhou 310014,China)

机构地区：[1]国网浙江省电力有限公司电力科学研究院,浙江杭州310014 [2]杭州意能电力技术有限公司,浙江杭州310014

出　　处：《电工电气》2024年第10期31-36,72,共7页Electrotechnics Electric

基　　金：国家电网有限公司科技项目(5500-202419163A-1-1-ZN)。

摘　　要：近年来高压电缆护层保护器击穿烧毁故障频出,为优化电缆接地系统设计并为保护器选型提供参考,利用电磁暂态仿真软件PSCAD/EMTDC建立电力电缆线路模型。结合实际工程中长电缆线路各类接地方式,对单相接地故障期间不同电缆长度、接地电阻、敷设回流缆的护套沿线过电压变化规律进行研究。研究结果表明,电缆末端单相接地故障后,220 kV交叉互联电缆护套沿线过电压水平在2~8 kV;对交叉互联混合单端/中间接地方式,护套连接处存在地电位升高特性,严重时达16 kV;敷设回流缆对单端接地方式电缆护套过电压抑制效果明显,利于保护器选型。In recent years,there have been frequent breakdowns and burnout faults in the sheath protector of high-voltage cables.To optimize the design of the cable grounding system and provide a reference for protector selection,the electromagnetic transient simulation software PSCAD/EMTDC is used to establish a power cable line model.Considering various grounding methods for long cable lines in practical engineering projects,the study investigates the variation patterns of sheath overvoltage along line during single-phase grounding faults,with respect to different cable lengths,grounding resistances,and the installation of return cables.The research results show that after a single-phase grounding fault at the end of the cable,the overvoltage along line level of the 220 kV cross-interconnection cable sheath ranges from 2~8 kV.For the cross-interconnection hybrid single-end/mid-point grounding method,there is a characteristic of increased ground potential at the sheath connections,which can reach as high as 16 kV in severe cases.The installation of a return cable has a significant effect in suppressing the overvoltage of the cable sheath in the single-end grounding method,which is beneficial for the selection of protectors.

关 键 词：高压电缆 金属护套 交叉互联 过电压 回流缆 保护器 接地电阻 

分 类 号：TM726.4[电气工程—电力系统及自动化] TM866