Analysis of rail potential and stray current in MVDC railway electrification system

Abstract In contrast to the conventional direct current railway electrification system (DC-RES), the medium voltage direct current (MVDC)-RES is considered promising for long-distance high-speed corridors. In the MVDC-RES, traction substations (TSSs) are placed much farther and train loads are much heavier than in the conventional DC-RES. Hence, the MVDC-RES brings a drastic change in catenary voltage, TSS spacing, and train loading, which affects rail potential and stray current. In this connection, this work performs some significant quantitative analysis of rail potential and stray current in the MVDC-RES environment. An MVDC simulation model is proposed and different grounding schemes are analyzed for a single-train and two TSSs scenario as well as for a multi-train multi-TSS scenario. According to the simulation and analysis, the maximum values of rail potential and stray current at MVDC-RES distances and the maximum safe distance between adjacent TSSs are determined.