摘要
直流输电一般采用双极两线-地制构成方式,接地极线路从换流站引出到接地极,接地极尺寸近100万平方米。随着华南地区直流输电线路的增加,接地极的建设选址愈发困难,同时造成大量的土地占用,并且两变电站间若存在较大电位差将引起交流系统的直流偏磁效应。为此研发了深井接地极和共用接地极技术,建设世界首例千米级深井接地极,节约极址占地面积90%,接地极电阻减少2/3,接触电势降低80%。依据中国南方电网实际直流工程介绍EHVDC的建模仿真方法,分析了两条超高压直流输电线路电磁环境和直流线路与接地极线路同塔架设对共用接地极及其线路电气特性影响。
The direct current transmission generally adopts a bipolar two-wire-ground system.The grounding electrode line is led from the converter station to the grounding electrode,and the grounding electrode size is nearly 1 million square meters.With the increase of DC transmission lines in South China,the construction and site selection of grounding electrodes has become increasingly difficult.A large amount of has been land occupied,and if there is a large potential difference between the two substations,it will cause the DC bias effect of the AC system.To this end,a deep well grounding electrode and common grounding electrode technology are developed.The world's first kilometer-level deep well grounding electrode is built,which savad 90%of the area of the pole site,reduced the grounding electrode resistance by 2/3,and reduced the contact potential by 80%.According to the actual DC project of China Southern Power Grid,the modeling and simulation method of EHVDC is introduced.The electromagnetic environment of two UHV DC transmission lines and the influence of the DC line and the grounding electrode line on the same tower on the common grounding electrode and its electrical characteristics are analyzed and calculated.
作者
李坤泉
李瑞芳
杜浩
曹晓斌
胡上茂
刘刚
LI Kunquan;LI Ruifang;DU Hao;CAO Xiaobin;HU Shangmao;LIU Gang(College of Electrical Engineering,Southwest Jiaotong University,Chengdu 611756,China;High Voltage Research Institute,CSG Electric Power Research Institute,Guangzhou 510663,China)
出处
《电工技术》
2021年第16期124-128,共5页
Electric Engineering
关键词
超高压直流输电建模
深井接地极
共用接地极
接地极线路电流
地表电位
电磁场
直流偏磁
UHV DC transmission modeling
deep well grounding electrode
common grounding electrode
grounding electrode line current
ground surface potential
electromagnetic field
DC bias
