Study on influencing factors of rail potential in DC metro system

In DC metro systems, in the DC power supply system, the rail, as a backflow rail, transmits the current flowing into the rail of a train to the negative pole of the traction power station. On the one hand, the increase of rail potential will lead to the intensification of stray current. On the other hand, it will threaten personal safety. Therefore, it is necessary to reduce the rail potential when the DC metro system is running. In order to obtain rail potential, a DC power supply system is built to simulate different conditions of the actual metro line by CDEGS software. The simulation results show that the rail potential has a certain variation rule. The rail potential increases greatly when the traction power station or brake train outside the power supply section to the train inside the section, and the traction backflow resistance and power supply mode also affect the rail potential.