Influence of Protection Wire and Positive Feeder Arrangement of Traction Network on the Return Current in High-speed Railway

High-speed railway is powered by overhead high-voltage transmission lines. The protection wire and positive feeder of traction network usually descend from overhead to the ground along the track in the station due to space constraint. In this case, based on the Multi-conductor Transmission Lines (MTL) theory, the mathematical model of the traction network in AT power supply for high-speed railway is established, and the behavior of the return current is considered. This work investigates the influence of protection wire and positive feeder laid on the ground, which provides a research basis for the protection of trackside equipment. The simulation results show that the return current on the rail and positive feeder are increased, which should be considered in engineering practice.