大型变电站接地网的故障特性分析  

Fault Characteristic Analysis of Grounding Grid in Large Substation

作　　者：鲁志伟[1] 吴传斌 张迎栋 冷赫 LU Zhiwei;WU Chuanbin;ZHANG Yingdong;LENG He(Northeast Electric Power University,Jilin 132012,China)

机构地区：[1]东北电力大学,吉林吉林132012

出　　处：《吉林电力》2022年第3期37-42,共6页Jilin Electric Power

摘　　要：为了更全面地了解大型变电站接地网的故障特性,对故障接地网模型进行仿真计算,总结了不同故障情况对接地网的工频接地电阻和冲击接地电阻、接触电压和跨步电压以及地表电位和磁场强度大小的影响规律,得出:靠近电流注入点区域的接地导体腐蚀对工频接地电阻和冲击接地电阻的影响较大;在靠近电流注入点区域的接地导体发生腐蚀时,此区域内接地网的接触电压和跨步电压明显增大,甚至可能增大数倍;接地网出现故障后导体散流能力下降,导致对应区域的地表电位和磁场有不同程度的降低,并且在相同的故障条件下地表磁场降低的范围较大。In order to have a more comprehensive understanding of the fault characteristics of ground grid of large substation,the model of fault ground grid is simulated and calculated,and the influence rules of different corrosion zones and different corrosion degrees on power frequency grounding resistance and impact grounding resistance,contact voltage and step voltage of the butt ground grid are summarized.And the influence of different fault types and different fault degrees on the surface potential and magnetic field intensity of ground grid.The calculation shows that the corrosion of grounding conductor near the current injection point has great influence on the power frequency grounding resistance and impact grounding resistance.When the grounding conductor near the current injection point is corroded,the contact voltage and step voltage of the grounding grid in this area increase significantly,or even several times.When a grounding network fault occurs,the conductor’s divergence ability decreases,resulting in varying degrees of decrease in the surface potential and magnetic field in the corresponding area.The surface magnetic field responds more sensitively to grounding network faults.

关 键 词：大型变电站 接地网 故障 接地电阻 接触电压 跨步电压 地表电位 地表磁场 

分 类 号：TM89[电气工程—高电压与绝缘技术]