轨道交通杂散电流对交流电网变压器偏磁直流影响因素分析  

Factors of stray current in rail transit affecting DC magnetic bias of AC power grid transformer

作　　者：张璐科 暴家良 李晓华 陈璐 ZHANG Luke;BAO Jialing;LI Xiaohua;CHEN Lu(College of Electrical Engineering,Shanghai University of Electric Power,Shanghai 200090,China;Anyang Power Supply Company,State Grid Henan Electric Power Company,Anyang 455000,China;State Grid Shanghai Municipal Electric Power Company,Shanghai 200122,China)

机构地区：[1]上海电力大学电气工程学院,上海200090 [2]国网河南省电力公司安阳供电公司,河南安阳455000 [3]国网上海市电力公司,上海200122

出　　处：《电力科学与技术学报》2024年第6期79-91,共13页Journal of Electric Power Science And Technology

基　　金：国家自然科学基金(51607110)。

摘　　要：城市轨道交通杂散电流在大地中流动分布时会侵入附近交流电网变压器。为研究不同土壤特性下轨道交通杂散电流对沿线变电站的偏磁影响,基于上海某变电站及其邻近轨道交通系统,利用CDEGS软件建立城市轨道交通‒交流电网变电站耦合仿真模型,对不同混凝土、土壤电阻率下杂散电流对交流电网变压器偏磁直流影响进行研究,并利用土壤等电流密度幅值分布曲线,结合可视化技术显示杂散电流的影响范围与流通路径。结果表明,混凝土电阻率和土壤电阻率对钢轨泄漏电流空间电场分布和变压器中性点偏磁直流影响存在较大差异。在仿真模型中,杂散电流的最大影响范围为1421.33 m,以分布距离与土壤电阻率的微分作为土壤电阻率对杂散电流流动范围影响指标,土壤电阻率最大为1.42 m/(Ω⋅m)。列车启动33 s后行至500.3 m位置处,土壤电阻率对变电站中性点偏磁直流影响最大,可达0.003431 A/(Ω⋅m)。The flow distribution of stray current in urban rail transit in the ground makes it intrude into the nearby alternating current(AC)power grid transformer.In order to study the influence of stray current in rail transit on the magnetic bias of substations along the line under different soil characteristics,based on a substation in Shanghai and its nearby rail transit system,CDEGS software is used to establish the coupling simulation model of“urban rail transit-AC power grid substation”,so as to study the influence of stray current on the direct current(DC)magnetic bias of the AC power grid transformer under different concrete-soil resistivity.The distribution curve of soil iso-current density amplitude is used,combined with visualization technology,to display the influence range and flow path of stray current.The results show that there is a big difference in the influence of concrete resistivity and soil resistivity on the spatial electric field distribution of the leakage current of the rail and the DC magnetic bias of the neutral point of the transformer.In the simulation model,the maximum influence range of stray current is 1421.33 m,and the differential of distribution distance and soil resistivity is used as the influence index of soil resistivity on the flow range of stray current.The maximum soil resistivity is 1.42 m/(Ω⋅m).When the train moves 500.3 m after 33 s,the soil resistivity has the greatest influence on the DC magnetic bias of the neutral point of the substation,which can reach 0.003431 A/(Ω⋅m).

关 键 词：地铁杂散电流 偏磁直流 耦合仿真 CDEGS 动态变化 土壤电阻率 

分 类 号：TM401.1[电气工程—电器]