城市轨道交通动态运行对交流电网变压器偏磁直流的影响  

Influence of Dynamic Operation of Urban Rail Transit on DC Magnetic Bias of AC Power Grid Transformer

作　　者：黄华 陈璐 吴天逸 傅晨钊 暴家良 李晓华 HUANG Hua;CHEN Lu;WU Tianyi;FU Chenzhao;BAO Jialiang;LI Xiaohua(State Grid Shanghai Electric Municipal Power Company,Hongkou District,Shanghai 200122,China;School of Electrical Engineering,Shanghai Electric Power University,Yangpu District,Shanghai 200090,China)

机构地区：[1]国网上海市电力公司,上海市虹口区200122 [2]上海电力大学电气工程学院,上海市杨浦区200090

出　　处：《电网技术》2022年第11期4524-4533,共10页Power System Technology

摘　　要：为研究城市轨道交通动态运行杂散电流引起的交流电网变压器偏磁直流特性规律,该文首先推导了“钢轨-排流网-结构钢筋-大地”4层结构双边供电电阻网络解析模型和杂散电流引起变压器偏磁直流的一般数学模型,然后利用CDEGS(current distribution, electromagnetic fields, grounding,soil structure analysis)接地分析软件基于上海某500kV变电站及其附近轨道交通建立“轨道交通系统-变电站交流电力系统”耦合仿真模型,对地铁单列车、多列车动态运行时轨道交通侧杂散电流、变压器中性点直流变化规律及其影响因素进行研究,并通过与现场实测数据对比验证了仿真模型和结论的正确性。结果表明:基于上海某500kV变电站及其附近轨道交通仿真模型中,单列车运行最大可造成500kV变压器2.3A的偏磁直流,多列车双向运行时最大可造成变压器12.4A的偏磁直流,仿真结果与现场实测结果符合度较高,具有统计学意义。变压器中性点电流幅值大小主要取决于变电站与地铁的相对位置、土壤电阻率、和变电站接线方式。最后该文仿真证明,在上海某500kV变电站及其附近轨道交通系统模型中变压器中性点加装3Ω限流电阻时可获得较好直流抑制效果。In order to study the DC characteristics of the AC grid transformer bias caused by the stray currents in the urban rail transit dynamic operation, this paper first derives the "rail-drain network-structure steel-earth" four-layer doublesided power supply resistor network analytical model and the general mathematical model for the transformer bias DC caused by the stray currents. Then by using the CDEGS(current distribution electromagnetic fields grounding,soil structure analysis)ground analysis software, a "rail transit systemsubstation AC power system" coupling simulation model is established based on a 500kV substation in Shanghai and its nearby rail transit. The stray currents on the traffic side, the DC change rules on the transformer neutral points and their influencing factors are studied, and the correctness of the simulation model and the conclusions is verified by comparing with the field measured data. The results show: Based on the 500kV substation in Shanghai and its nearby rail transit simulation model, a single train operation can cause a maximum of 2.3A magnetic bias DC of the 500kV transformer,and a maximum of 7.1A magnetic bias DC of a transformer when multiple trains operate in both directions. Simulation results agree highly with the on-site measured results, which is statistically significant. The magnitude of the current amplitude at the neutral point of the transformers mainly depends on the relative position of the substation and the subway, the transition resistance of the rail to the ground, the soil resistivity, and the wiring modes of the substation. Finally, the simulation in this paper proves that a better DC suppression effect will be obtained in the 500kV substation when a 3Ω current-limiting resistor is installed at the neutral point of the transformer.

关 键 词：轨道交通 杂散电流 耦合仿真 中性点电流 CDEGS 限流电阻 

分 类 号：TM721[电气工程—电力系统及自动化]