特高压直流接地极线路内部过电压机理及特性分析  

Mechanism and Characteristics of Internal Overvoltage in UHVDC Grounding Electrode Line

作　　者：刘守豹 张星海 曾宏 雷潇 廖文龙 LIU Shoubao;ZHANG Xinghai;ZENG Hong;LEI Xiao;LIAO Wenlong(State Grid Sichuan Electric Power Research Institute, Chengdu 610094, Sichuan Province, China)

机构地区：[1]国网四川省电力公司电力科学研究院

出　　处：《电网技术》2018年第7期2366-2372,共7页Power System Technology

摘　　要：接地极线路是特高压直流输电系统的重要组成部分,为对特高压直流接地极内部过电压机理及特性进行分析,介绍了接地极线路电压响应传递函数,使用电力系统分析软件MATLAB Sim Power System建立了±800 k V宾金直流工程过电压计算模型,对紧急停运、接地极线路单侧接地、直流系统高压侧接地3种情况下接地极线路的内部过电压进行了比较,重点分析了高压侧接地点位置、直流滤波器、高压直流线路长度、接地极线路长度对单极故障下接地极线路内部过电压的影响。分析表明高压侧接地所导致的接地极线路内部过电压最严重;接地极线路长度、直流线路长度和高压侧故障点位置影响接地极线路内部过电压幅值和频率,直流滤波器则决定了过电压振荡频率;直流接地极线路绝缘水平应根据直流工程具体情况确定。Grounding electrode line is an important part of UHVDC transmission system. In this paper, transfer function of internal overvoltage response in grounding electrode line was derived. Yibin-Jinhua ±800 kV UHVDC project was taken as research object, and power system analysis software MATLAB Sim Power System was used to establish a simulation model. Three types of internal overvoltage in grounding electrode line are compared in cases of emergency shutdown, one side of grounding electrode line grounding and high voltage side grounding. Influence of DC filter, HVDC transmission line length and ground electrode line length on internal overvoltage of grounding electrode line caused by high voltage side grounding was emphatically analyzed. Analysis showed that this internal overvoltage was the most serious. Length of ground electrode line, length of HVDC transmission line and position of earthing point had influence on amplitude and frequency of overvoltage; DC filter determined voltage oscillation frequency. DC grounding electrode line insulation level should be determined according to specific situation of UHVDC project.

关 键 词：特高压直流 接地极线路 内部过电压 外绝缘配置 传递函数 紧急停运 

分 类 号：TM721[电气工程—电力系统及自动化]