Modelling and Simulation of Stray Current in Urban Rail Transit—A Review

With the rapid development of urban rail transit, the issue of stray current due to incomplete insulation between the rail and the earth is attracting increasing attention. Stray current seriously affects the safe operation of urban rail transit, pipelines and power grids, and pose challenges to the development of urban energy security. However, there are significant differences among the various methods for the analysis and verification of stray currents, and existing research works thus lack a mature theoretical framework. To address this, this paper presents an in-depth review on the study of stray current including the mechanism, technical standards, modelling, simulation and mitigation technologies. Firstly, the principle and standards of stray current are introduced from multiple perspectives (i.e. metro side, pipeline side and grid side). Then, the typical modelling and simulation of stray current are summarized and compared in detail. The representative stray current mitigation measures, together with the stray current hardware simulation technologies, are also discussed. In conclusion, this paper provides a comprehensive overview of key technologies involved in the modelling and simulation of stray current, and highlights the valuable research direction in stray current mitigation.