城轨杂散电流对电缆互联城网变压器的影响与治理  

Urban Rail Stray Current Effects and Mitigation for Transformers of Cable Interconnected Urban Power Grid

作　　者：郭志广 贾跟卯 王振刚 陈璐 王瑞田 骆福权 GUO Zhi-guang;JIA Gen-mao;WANG Zhen-gang;CHEN Lu;WANG Rui-tian;LUO Fu-quan(Beijing State Grid Fuda Technology Development Co.,Ltd.,Beijing 100070,China;State Grid Shanghai Power Company Power Research Institute,Shanghai 200437,China)

机构地区：[1]北京国网富达科技发展有限责任公司,北京100070 [2]国网上海市电力公司电力科学研究院,上海200437

出　　处：《变压器》2022年第10期16-25,共10页Transformer

基　　金：国家电网有限公司科技项目资助(项目编号:520940200013)。

摘　　要：针对华东超大城市3座500kV及8座220kV变电站受城轨杂散电流影响的变压器,经大规模系统性监测发现,变压器受200m~3000m距离范围内杂散电流的侵入影响普遍且严重。电网建模计算表明,归算电阻值小于0.1Ω的电网及其良好的电站接地系统,可在城区形成约3V~5V的局部杂散电流电位塌陷区,吸引轨道沿线20V~300V高电位钢轨泄漏的杂散电流流入。采用在中性点加1Ω~3Ω电阻和2Ω~6Ω电抗的绕线式有感电阻的方式,可阻塞并转移全部杂散电流、有效限制电网单相接地故障时变压器中性点出现的3I0短路电流。A large-scale systematic monitoring for transformers in three 500kV and eight220kV substations affected by urban rail stray current in East China shows the fact that transformers were intruded widely and seriously by the stray current of urban rail in the distance range of 200m ~3000m. By calculation of power grid modeling shows that, a very low equivalent resistance value of less than 0.1Ω between the S/S and near urban rail, and the good substation grounding system form a local potential collapse area of about 3V~5V in the urban area, which has a strong attraction effort for the stray current which dispersed along the 20V~300V high voltage level steel rail of railway line. By installing a new type winding coil resistor with reactance in neutral point,most stray currents can be blocked through 1Ω~3Ω resistance and shift it to the cable metallic outer sheath way, by the additional 2Ω~6Ω reactance could effectively limit the 3I0short-circuit current when a single-phase grounding fault occurs in the power grid.

关 键 词：变压器 城轨杂散电流 统计特征值 绕线式有感电阻 

分 类 号：TM401.2[电气工程—电器]