接地极选址方法研究

Research on Location Method of Earth Electrode

接地极作为高压直流输电系统的重要组成部分,当较大的直流电流经接地极注入大地时,会在极址土壤中形成一个恒定的直流电流场,出现大地电位升高,对周边环境带来不容忽视的影响。针对接地极的直流偏磁影响,研究了不同的土壤结构对接地极周边地表电位的影响,以及接地极周边变压器分布对变压器直流偏磁的影响。提出了降低接地极直流偏磁影响的接地极选址的优化方法 :在接地极选址过程中通过分析极址区域土壤电性结构及其周边电力系统分布,预估接地极对周边变压器的直流偏磁影响,为接地极选址提供参考意见,为后续直流工程接地极选址提供借鉴和参考。

Earth Electrode is an important part of HVDC system. When a strong current is injected into earth through electrode, there will be a constant current field in the earth, with raised earth potential, lead to DC magnetic bias effect to the power system. This paper studies the effect of different grid structure on the earth potential and DC Magnetic Bias Effect to the Power System. This paper proposes the optimization method of earth electrode site selection for reducing the DC magnetic bias effect to the power system： the magnetic bias effect can be qualitatively pre-estimated by analyzing the grid structure and the power system of the surrounding, which can provide reference comments to the electrode site selection. This method provides reference to the following electrode site selection of HVDC project.