Study On The Modification Scheme Of The Traction Power Supply System Of High-speed Railway Based On The Measured Data Of Traction Load

As a new card for China to go out,"high-speed rail diplomacy" makes the strength and scale of the high-speed railway technology in China are fully demonstrated.The high-speed railway in China has become the fastest growing one in the world,which has the longest running mileage,the highest speed of operation,the largest construction in scale,the most complete system technology.The traction power supply system,as the key part of the high-speed railway,whose safe,reliable and economical operation plays a decisive role in the high-speed railway transport.The internal high-speed railway been built or building are designed in accordance with the long-term traffic.However,the high-speed railway often has a small transport volume in the early stage of operation,that makes the capacity of the power supply equipment idle,thus the system economy operation is endangered.Moreover,the safe,reliable and economical operation of the high-speed railway has been restricted by the problem of passing the neutral section.To improve the above problems in a comprehensive way,the best measure is to reform traction substation succinctly.Firstly,in combination with the Beijing-Shanghai High-speed Railway project and actual measurement data of the traction substations,the problems existing in the current high-speed railway operation are specifically pointed out.And then two kinds of schemes of transforming the traction substation are put forward,in order to comprehensive improve the status and effectively enhance the safety and economy of high-speed railway operation at a low cost.Secondly,the electrical analysis of the all-parallel AT traction power supply system in the Japanese model and the French model are carried out,and the simulation model of the all-parallel AT traction power supply system in the Matlab/Simulink software based on the actual parameters of the high-speed railway line is built.Considering the different train tracking interval and position situations,the traction grid voltage as one of the most important power supply indexes is checked under the schemes of transformation.With the negative sequence current general expression and the proportional relation between the three-phase voltage imbalance degree and the negative sequence current,the three-phase voltage imbalance degree as another key power supply index is checked under the schemes of transformation.And the ampacity of an overhead contact system from two power supply arms of a high-speed railway traction substation is checked under the schemes of transformation.Then using the calculation model and method of traction transformertemperature rise and life loss,according to the actual load data of the traction substation,the traction transformer temperature rise and life loss are analyzed under the schemes of transformation to test the capacity of traction transformer.The results of verification show that both of the two schemes have excellent feasibility,and effectively reduce the number of neutral section as well as improve the capacity utilization of power supply equipment.Finally,after discussing the feasibility of the two schemes of transformation,the economy of the two schemes of transformation is analyzed from the angle of electric charge change.Then the segment power supply and measurement control technology is used to effectively improve the reliability of the system operation.