高压直流输电单极大地方式运行时地表电位分布规律

Earth surface potential distribution of HVDC operation under monopole ground return mode

采用有限元方法分析了直流单极大地方式运行时大范围的地表电位分布特征,并通过ANSYS软件计算了浅层和深层2种土壤结构模型下的地电位分布;同时考虑了有变电所出线、不同变电所接地电阻、江河以及湖泊等多种情况下对地电位分布的影响。研究结果表明:土壤结构对地表电位分布影响较大,采用土壤深层模型时计算结果更为准确;变电所架空出线距离直接接地极越近、线路越长、线路回数越少,其两端的电位差越大;河流对地表电位影响较小,湖泊边缘处对地表电位影响较大。

The long-range distribution features of ESP（Earth Surface Potential） of HVDC operation under monopole ground return mode are analyzed by finite element method,and the distributions of both shallow and deep soil structure models are calculated with ANSYS. The influences of substation outlet,substation earthing resistance,river and lake are taken into account. Results show that,soil structure has notable effect on surface potential and the computed result with the deep soil structure model is more accurate; the shorter the distance between substation overhead outline and grounding electrode is,or the longer the line is,or the fewer lines there are,the greater the potential difference between two line ends is. The river affects the ESP weakly while the edge of lake does comparatively strongly.