Operational Evaluation Of Network Pressure And Temperature Rise Characteristics Of Beijing-zhangjiakou High-speed Railway Trains

The Beijing-Zhangjiakou high-speed railway and the related EMUs are important supporting facilities for the 2022 Winter Olympics in my country.Evaluating the network pressure and temperature rise characteristics of the Beijing-Zhangjiakou high-speed railway is of great significance to the current and future development of the line.This paper takes the 25 k V traction network,the train traction transformer,the grid-side converter and the equivalent DC side load as the research objects,and adopts the method of building a simulation model of the whole train to evaluate the operation of the train when it runs on the line.It provides data support and effective guarantee for the safe operation of trains on the line now and in the future,and can also provide data support for research work in the direction of train subsequent capacity configuration,life prediction of electrical equipment,and fault diagnosis.The specific research work is as follows:Aiming at the problem that the line conditions of the Beijing-Zhangjiakou highspeed railway and vehicle operating conditions cause fluctuations in the traction network pressure,the Beijing-Zhangjiakou high-speed railway traction network is modeled.Firstly,the power supply mode of the traction network of the Beijing-Zhangjiakou highspeed railway is introduced,and the impedance parameters of each conductor of the traction network under this power supply mode are calculated and analyzed.Secondly,the equivalent impedance parameters of the traction network and the network voltage changes are analyzed when the train runs in different locations and under different working conditions,and the calculation results are used for subsequent simulation and evaluation of the network voltage across the entire line.Aiming at the problem of reflecting the temperature rise characteristics of key electrical equipment during train operation,a temperature rise model of train traction system including traction transformer and grid-side converter is established.First,build the main circuit model of the Beijing-Zhangjiakou high-speed train traction system,and study the control algorithm of the train grid-side converter.Secondly,the temperature rise model of traction transformer and grid-side converter power module is established to evaluate the temperature change during train operation.Finally,based on the data from the temperature rise test report of the Beijing-Zhangjiakou high-speed rail vehicle traction transformer and traction converter,the validity and correctness of the temperature rise model are verified by simulation.Aiming at the problem of equivalent load on the DC side of the grid-side converter during the operation of the train on the Beijing-Zhangjiakou high-speed railway,based on the line data of the Beijing-Zhangjiakou high-speed railway,the equivalent calculation of the DC-side load on the Beijing-Zhangjiakou high-speed railway is carried out.First,the modeling method of the equivalent DC side load of the train rectifier is studied.Secondly,by writing the calculation program of the equivalent load,the load equivalent of the train in the running process of the upstream and downstream lines is realized.Through the comparative analysis of the calculation results and the actual line conditions,the rationality of the calculation results of the DC side equivalent power is demonstrated.Based on the built traction network,train traction system and equivalent load model,the operation evaluation simulation and analysis are completed for the train operation evaluation problem on the whole line.First,the voltage fluctuation of the traction network of the train running on the entire line is simulated;secondly,the temperature rises variation of the traction transformer and the traction converter of the train is simulated;finally,the simulation results are analyzed and the evaluation conclusions are given.Figures: 89,Tables:10,References:65.