某110kV变电站接地网问题分析与改造措施

Analysis on problems of grounding grid of an 110kV substation and modification measures

本文根据对某110k V变电站的现场调查结果,对该变电站接地网接地阻抗超标和围墙边缘电位梯度过大,且经过改造之后仍然无法达到要求的问题进行了分析。并结合周围地形、土壤电阻率的实际情况,采用了外延法、降阻剂法和深井接地法以降低接地阻抗,并在变电站围墙四周铺设了立体均压环以改善电位分布。经过计算和试验证明,改造方案达到了预期的效果。

For a substation, the ground impedance of the grounding grid could exceed standard and the electric potential gradient at the edge of enclosing walls could be excessively high, even after modification. An analysis on this issue is made in the paper. Based on the actual situation of surrounding to pography and earth resistivity, epitaxial method,drag reduction agent method and deep well grounding method are adopted, and stereoscopic grading rings are laid surrounding the enclosing walls of the substation to improve potential distribution.