地铁杂散电流引起变压器直流偏磁电流的相关性分析  

A correlation analysis on transformer DC bias current caused by metro stray current

作　　者：倪砚茹 喻锟 曾祥君[1] 冷阳 彭平 周卫华 谢耀恒 NI Yanru;YU Kun;ZENG Xiangjun;LENG Yang;PENG Ping;ZHOU Weihua;XIE Yaoheng(School of Electrical&Information Engineering,Changsha University of Science&Technology,Changsha 410114,China;Electric Power Science Research Institute,State Grid Hunan Electric Power Co.,Ltd.,Changsha 410007,China)

机构地区：[1]长沙理工大学电气与信息工程学院,湖南长沙410114 [2]国网湖南省电力有限公司电力科学研究院,湖南长沙410007

出　　处：《电力科学与技术学报》2021年第6期136-143,共8页Journal of Electric Power Science And Technology

基　　金：湖南省研究生科研创新项目(CX20210787);湖南省高校创新平台开放基金(20K003);国家电网总部科技项目(5100-202199276A-0-0-00)。

摘　　要：地铁运行过程中泄露的杂散电流导致附近地表电位发生改变,使各个接地变压器处于不同的地电位上,引发变压器的直流偏磁。为探究地铁杂散电流引起变压器直流偏磁电流之间的数值关系,针对地铁的双端供电模式的运行环境,研究地铁供电系统中杂散电流泄露方式与引起变压器直流偏磁的流通路径,揭示地铁运行过程中变压器直流偏磁的产生机理;基于双端供电的杂散电流分布离散模型,考虑杂散电流的泄露路径对变压器直流偏磁的作用机理,搭建杂散电流引起变压器直流偏磁电流的等效电阻模型,建立变压器直流偏磁电流随地铁运行工况变化的计算方程,实现由杂散电流引起的沿线变压器中性点直流电流的数值分析与计算;利用CDEGS仿真模型验证该模型的有效性,能够准确计算地铁站附近的变压器中性点直流偏磁电流,对地铁站、变电站的规划建设具有一定的指导意义。The leaked stray current during the metro operation causes a change of the nearby surface potential,which results in a variation of the ground potential of grounding transformers,then the transformer DC bias.By studying the stray current leakage mode in the traction power supply system for rail transit and the flow path which causes the transformer DC bias,the mechanism of transformer DC bias generated by the metro stray current is revealed.With the consideration of the action mechanism of stray current on transformer DC bias,the equivalent resistance model of the transformer DC bias caused by the stray current is built with double-end power supply which is based on the discrete model of the stray current distribution.The mathematical equation of the transformer neutral point current with the changing operating conditions of the rail transit is established,and the numerical calculation of the transformer neutral point is realized.The validity of the model is verified by the CDEGS simulation,which has certain guiding significance for the planning and construction of subway stations and substations.

关 键 词：地铁牵引供电系统 地铁杂散电流 地表电位 变压器直流偏磁电流 

分 类 号：TM401.1[电气工程—电器]