Study on Rail Potential of Metro Traction Power Supply System

Rail over-potential is one of the main problems of DC traction supply system. Firstly, based on the problem of rail over-potential, this paper introduces the comprehensive grounding system of metro substation and the structure of stray current returning ground network. Then, relative research methods and results of rail potential and its distribution are summarized, compared and evaluated. Meanwhile, various protective measures at present are summarized and evaluated according to the influence factors of rail potential. Finally, opinions about the ideas and methods of researching the rail potential of metro are put forward, and the research prospect is prospected.