接地极极址对电网直流偏磁影响的研究

Study on the Effect of Grounding Electrode Site on DC Bias Magnetization of Power Grid

为分析酒泉至湖南±800kV特高压直流输电工程接地极选址对当前酒泉电网的影响,需建立酒泉地区交流电网直流电流分布模型.根据酒泉地区交流电网拓扑结构,基于场路耦合方法,将包括变压器、线路的地上模型和包括接地电阻、地表电位的地下模型予以结合,建立酒泉地区交流直流电流分布模型,通过仿真计算,分析初步规划的西涧泉或红柳沟接地极址对甘肃电网直流偏磁影响,得到了酒泉至湖南±800kV特高压直流输电工程最佳选址地点.

In order to analyze the effect of grounding electrode location of Jiuquan-Hunan !800kV UHVDC transmission project on Jiuquan grid, AC/DC current distribution model is built in Ji- uquan area. According to the alternate current network topology structure in Jiuquan area, and based on the field circuit coupling method,AC/DC current distribution model is established in Ji- uquan area by combining the surface model including transformer and transmission line and the subsurface model including ground resistance and surface potential. By simulation calculation,the effect of the preliminarily planned grounding site in Xijianquan or Hongliugou on DC bias magnet- ization of Gansu power grid is analyzed,and the best location of Jiuquan-Hunan ＋800kV HVDC transmission project is obtained,which provides the valuable reference for the safe and reliable op- eration of the grid.