带分流系数的变电站接地网测试评估方法探讨  

Discussion on Test and Evaluation Method of Substation Grounding Grid With Shunt Coefficient

作　　者：田妍 郑服利 姚彤 李纯 王羽[2] 文习山[2] TIAN Yan;ZHENG Fuli;YAO Tong;LI Chun;WANG Yu;WEN Xishan(Test and Research Institute of Guangzhou Power Supply Bureau,Guangzhou 510410,China;School of Electrical Engineering,Wuhan University,Wuhan 430072,China)

机构地区：[1]广州供电局电力试验研究院,广州510410 [2]武汉大学电气工程学院,武汉430072

出　　处：《电瓷避雷器》2018年第5期140-145,共6页Insulators and Surge Arresters

摘　　要：在对变电站接地网状态测试评估中,接地阻抗是一个重要参数。在实际测量中,很难断开架空地线与地网之间的联系。但若要准确计算得到变电站的接地阻抗值,则需要对接地网的分流系数进行测量。而对于大型变电站,分流系数的测量十分繁琐,且容易出现误差。根据国家相关标准可知,变电站的接地阻抗允许值是根据地电位升允许值、最大入地短路电流确定的。由此可以换种角度,通过测量计算变电站接地网的最大地电位升,与地电位升允许值比较来判断接地网的接地阻抗是否符合要求,即不需要准确测量得到变电站接地阻抗值。而测量计算接地网的地电位升不需要测量分流系数,这对实际接地网状态测试评估具有重要意义。The grounding impedance is an important parameter in the evaluation of substation grounding grid. In the actual measurement,it is difficult to disconnect the connection between the ground wire and grounding grid. In order to calculate the grounding impedance of the substation accurately,it is necessary to measure the shunt coefficient of the grounding grid. As for the large-scale substation,the measurement of the shunt coefficient is very complicated and prone to errors. According to the corresponding national standards,it can be seen that the allowable value of grounding impedance of substation is determined by the allowable value of ground potential rise and maximum ground short-circuit current. From this point of view,by measuring and calculating the maximum ground potential rise of the substation grounding grid,and then it can be judged whether the grounding impedance is satisfactory comparing with the allowable value of ground potential rise,which means that its meaningless to accurately measure the impedance value of substation ground. The measurement and calculation of the ground potential rise of the grounding grid does not need to measure the shunt coefficient,which is of great significance to the actual grounding grid test and evaluation.

关 键 词：变电站接地网 接地阻抗 地电位升 分流系数 接触电位差 跨步电位差 

分 类 号：TM862[电气工程—高电压与绝缘技术]