Study On Effects Of Traction Network Return Circuit Grounding System Of High Speed Railway On Rail Potential

With the development of the times and the sustained growth of China's national economy,railway as the core of China's transportation,Passenger traffic and freightage are serious saturation,The contradiction between transport capacity and traffic are very prominent,and become a bottleneck of the development of national economy,so the development of high-speed railway is one of the important means for resolve conflict between supply and demand, studying to develop high-speed railway have become a key point and urgent affairs for railway development in China. Electrical high-speed railway requires more reliable operational condition,for the safety of people and devices nearby the railway system,it is important and necessary to consider the rail potential and traction return circuit grounding and so on.Firstly,the advantages and disadvantages on Various alternate current power supply network(AC) are analysed at the beginning of the thesis,and the methods belonging to AC power supply system called autotransformer power supply(AT) and track-return with return conductor power supply (TRRC) are considered to be more conformable for high-speed electrified railway. Secondly,the safety problem of persons and equipments in and around railway system is analysed, control requirements of Rail potential are proposed. According to the basic theory of current feeding and earthing, rail potential distribution regularity and characteristic for different traction power supply system is deduced. By analyzing the influence of various parameters on rail potential, equipotential bonding and buried earth wire to reduce rail potential are proposed, and Combination of theoretical analysis the selection method of buried earth wire. Finally, the matrix theory ofπ-type equivalent circuit mathematical model is built and calculated using MATLAB programming. according to lots of simulations,facters infuencing value of rail potential is analysed under operation or fault conditons, spacing of equipotential bonding and integrated earth system have significant function for reduction of rail potential, And put forward a programme of integrated grounding system for reference.