作　　者： ; ; ;

机构地区： 清华大学

出　　处： 《陕西电力》 2007年第6期1-6,共6页

摘　　要： 直流输电系统单极大地回路运行时,直流电流通过变压器中性点流入变压器,造成直流偏磁问题。从深层接地极是否能够改善电流分布出发,研究深层垂直接地极的电位分布和溢流密度的计算方法,计算和比较了深层接地极在不同埋深时引起的地表电位大小,得出的结论是,接地极的埋深至多对接地极附近的土地表面电位有较大的影响,而对远方的电位影响不大。通过一个实际的500 kV电网的仿真,说明直流电流在交流电网中的分布受埋深的影响很小,通过深埋接地极无法有效地解决直流偏磁问题。 During monopolar operation of HVDC systems with ground return, a largescale DC enters into neutrals of transformers, which causes DC bias of transformers. This paper discusses the influences of deep hole ground electrode on DC current distribution and researches the potential distribution and current density. The ground voltage caused by deep hole ground in different depth is calculated and compared. The depth of ground only has influences on the ground potential near electrode and has less impact on that far from electrode. The results of a 500 kV power grid simulation have shown that the DC current distribution in AC power system varies little with the depth of electrode. Deep hole electrode is not effective for solving DC bias of transformers.

关 键 词： 直流输电 深层接地极 直流偏磁 电流分布

领　　域： [电气工程]