LAUSR

In the urban rail transit, the rail current leaks into the earth inevitably due to the incomplete rail-to-earth insulation. It then forms rail potential and stray current issues, which endanger the personal safety and cause metallic corrosions on running rails and the third-party infrastructures. For mitigating the rail potential and stray current, this article proposes a negative resistance converter traction power system (NRC-TPS) to reduce their generating sources by providing zero-resistance loops to the rail current. NRC-TPS is constructed by installing power electronics equipment directly in the conventional traction power system (CON-TPS) without modifying trains, rails, or tunnels, and so on. The operation principles, control strategies, and mitigation performance of NRC-TPS are discussed in detail. The modeling, simulation, and experimental results indicate that the rail potential and stray current are reduced in NRC-TPS compared with those of CON-TPS. The feasibility and practicability of NRC-TPS are also proved through these results.