Study on Ground Potential Distribution Caused by Subway Operation

Abstract

Urban rail transit has become an important basic public transport facility, is of great significance to urban development and economic construction. During the operation of subway locomotive, stray current will flow into the earth, resulting in the change of soil potential. Thus, it will lead to the neutral point grounded transformer DC bias and buried metal corrosion. Firstly, based on COMSOL finite element simulation software, a composite layered soil model was constructed to simulate the real soil environment. Secondly, according to the rail current distribution of two-terminal power supply, the stray current distribution model was constructed with locomotive position changing. Finally, the potential changes of grounded transformer and buried metal during subway operation was simulated. The research showed that the soil potential distribution change rate is related to the subway locomotive location. When the locomotive position is determined, the induced potential changes more rapidly in the higher soil resistivity, and there is a step change of potential at the soil layer boundary.