Analysis the Effect of Complex Soil Structure on Potential Distribution Caused by Metro Stray Current

The stray current of urban rail transit will lead to nearby soil potential change, which will cause transformer DC bias. Therefore, the calculation model of earth potential distribution was established based on complex soil structure in this paper Firstly, the traction power supply model of urban rail transit was established, and the analytical expression of stray current distribution was derived. Then, based on the numerical distribution results of metro stray current, the complex soil structure was established by finite element simulation software, and the soil potential calculation was realized. The simulation results showed that the soil structure has absolute influence on the change of earth potential distribution caused by metro stray current. With the greater the difference in soil resistivity of different layers, the influence on the soil potential is more obvious. The calculation of soil potential distribution caused by metro stray current can be realized, which has certain guiding significance for the evaluation of transformer DC bias.