Research On The Rail Traction Return Current And Property Of Rail Potential For High-Speed Electric Railway

With the development of the times and the continued growth of our national economy, passengers and freights traffic are severely saturated,the contradiction between transportation capacity and traffic are obvious.Building high-speed railway is an important means of solving the above problems.Because of the high traction load, rate of traffic flow, large traction current,the phenomenon of high rail potential is visible at the high-speed railway than general speed railway. The high railway potential has bad effects on personnel, equipment around the railway, the circuit of railway signal, the insulation between railway and sleeper, the distribution of traction current. it is very important for avoiding the high economic losses and major accidents to take effective measures to reduce the rail potential. the paper research the traction current and rail potential systematically.First of all,based on the measured data, the paper analyses the formation mechanism of the rail potential through the aspect of rail current;deduces the mathematical model of rail potential,rail current, ground surface potential nearby the railway; presents the attribute parameters of rail potential, verifies the theoretical analysis is correct by comparing the measured data.The paper builds models of traction power supply system and rail potential on general modules provided by MATLAB/Simulink. then studies and simulates the rail potential influencing factors which includes the mode of connection for traction transformer, the system of traction power supply, the type of locomotive,leakage resistance quantitativly. analyses the impact of rail potential on personal safty and equipment operation from the aspects of pace voltage and over voltage.deduces the mathematical model of pace voltage,calculates the probability of high rail potential for lighting.Based on theoretical analysis and field measurement data,presents the effective solutions for restraining the rail potential.In the end,develops a set of rail potential analysis system which can evaluate rail potential and current for different work condition.The research in the paper will help to improve the reliability and security of electric railway and provide the theoretical basis and parameters for the railway design and construction.