Study On The Feature Of Running-through Earth Wire And Impact On Traction Currents Distribution In High-speed Railway

In recent years,the rapid development of China’s high-speed railway has made the traction current and traction power larger than the existing lines,then rail potential and traction return were much increased.Chinese domestic research refers to the European integrated grounding,but traction power supply and signal system has not yet been a more complete integrated simulation.In particular,there is a lack of comprehensive analysis on the distribution of traction current and the main influencing factors.Therefore,this paper researches on the feature of running-through earth wire and impact on traction currents distribution in high-speed railway.Major work focuses the following four aspects:At first,according to major design parameters of high-speed railway traction power supply system,its specific impedance parameters were solved by existing impedance theoretical calculations,providing basic data support for subsequent simulation.Secondly,building a chain network model of traction network was to calculate the admittance matrix of all lines in traction network.Then continuous mathematical model of rail current and potential was deduced and the accuracy of system node model under single line AT power supply was verified.The variable parameters single line AT power supply was built.By comparison,the accuracy and the applicability of system node model were verified.Thirdly,the impact of ground parameters on rail current and potential were in-depth analyzed.Under the condition of different running-through earth wire diameters,current distribution ratio was obtained,and the impact on rail potential was analyzed.Finally,the time parameter tracking interval and speed level were introduced to analyze current distribution of the running-through earth wire in traction return system.Based on the characteristics of the 250km and the 350km per hour high-speed trains,the characteristics of the 400km per hour were derived to analyze the impact of the wire diameter on the leakage of the running-through earth wire.In conclusion,with the increase of running-through earth wire’s diameter,the current proportion of protective wire and running-through earth wire increase,but the current ratio of rail and the potential in each line reduce.In different diameters and ballast resistors,the distribution ratio of the running-through earth wire current in the transverse connection is the largest in the total currents.This paper presents the prediction and simulation data under certain conditions.The work of this paper has a certain reference for optimizing the design and selection of the running-through earth wire,reducing the cost of the project,reducing the rail potential and ensuring the safety of personnel and equipment.