中文摘要：

酒泉-湖南UHVDC等工程投运后，UHVDC接地极入地电流对极址附近变电站变压器的影响很大，其原因与极址大地电阻率模型建立不准确和地表电位分布计算不够精确有关。分析了直流输电接地极对周围地表电位造成的影响，并对直流输电接地极电流场的计算方法进行了整体推导。应用有限元方法，结合ANSYS软件，建立简单的土壤模型，求解运算生成接地极附近土壤表层电位分布图，并以此为基础建立了更贴近实际工况的多层复杂土壤模型，进行了仿真分析，结果能更直观表述接地极周围地电位的分布规律。

英文摘要：

With the Jiuquan-Hunan UI-IVDC project put into operation, the UHVDC grounding current on the electrode site exerts significant impacts on the nearby substation transformer, the reason of it is closely related to the inaccurate modeling of the soil resistivity on the pole site and the inaccurate calculation of the surface potential distribution. In this paper, the influence of the DC ground electrode of UHDC on the surrounding soil surface potential is analyzed and a calculation method of the current field of the DC grounding electrode is deduced. Using the finite element method, combined with soft-ware ANSYS, a simple soil model is established to generate the soil surface potential distribution map near the grounding electrode by solution calculation. On this basis, the multi-layered complicated soil model closer to the the actual working conditions is built for simulation analysis, resulting in more intuitive expression distribution of grounding electrode potential.