地铁牵引电流在列车运行中动态变化，导致周边电网回路中产生磁感应电压，由此产生的感应电流是致使变压器发生直流偏磁的关键问题之一。磁感应电压的产生受多种因素影响，为定量分析不同影响因素对其贡献度的大小，本文首先利用磁感应电压公式推导出地铁磁感应电压的主要影响因素，其次建立“地铁线路-输电线”磁耦合边界元模型，仿真分析了关键因素对感应电压的影响，在列车平稳运行阶段，感应电压受影响很小，在1000m处，感应电压已衰减了90%继而构建了产生磁感应电压的反向 (back propagation, BP) 神经网络，并采用平均影响值(mean impact value, MIV) 解析了各个影响因素对磁感应电压的贡献度，结果表明，等效回路中磁感应电压更易被等效回路长度影响，其贡献度为44.38%，相对距离的贡献度最小，仅为21.31%。因此电力系统构成等效回路的面积才是影响最终在闭合回路中产生磁感应电压值的最重要因素。

Metro traction current changes dynamically in train operation, resulting in magnetic induced voltage in the peripheral grid circuit, and the resulting induced current is one of the key issues that cause transformers to undergo DC demagnetization. The generation of magnetic induction voltage is affected by a variety of factors, in order to quantitatively analyze the size of the contribution of different influencing factors, this paper firstly uses the magnetic induction voltage formula to derive the main influencing factors of the magnetic induction voltage of the subway, and then establishes the "subway line-transmission line" magnetic coupling boundary element model to simulate and analyze the influence of the key factors on the induction voltage, and then analyzes the influence of the key factors on the induction voltage. In the stage of smooth running of the train, the induced voltage is affected very little, and at 1000m, the induced voltage has been attenuated by 90%, and then we constructed the back propagation (BP) neural network to generate the magnetic induced voltage, and analyzed the contribution of each influencing factor to the magnetic induced voltage by using mean impact value (MIV), which shows that the main influencing factors in the equivalent loop of the subway are the same as those in the grid, and the results show that the magnetic induced voltage in the equivalent loop is the same as that in the grid. The results show that the magnetic induction voltage in the equivalent loop is more likely to be influenced by the equivalent loop length, whose contribution is 44.38%, and the relative distance has the smallest contribution of 21.31%. Thus, it is the area of the power system constituting the equivalent loop that is the most important factor affecting the value of the magnetic induction voltage.

国网江苏省电力有限公司科技项目(J2022089)