Simulation Research On Transient Electrical Characteristics Of Electrified Railway

Electrified railway has many aspects of impact on the transient power quality of power system. The fluctuation of traction load is violent, frequent switching of the load results short time over-voltage phenomenon. The transformer magnetizing inrush current, the process of locomotive passing through neutral section, locomotive working conditions’changing also bring transient disturbance. National economy develops quickly, electrified railway shoulders an important role in transportation, the impact of it on transient power quality of power system can’t be ignored, therefore, the study on transient power quality problems that electrified railway brings to is very necessary.In the environment of matlab/simulink, the simulation model is build, the research on simulation of the mutation of traction load, the locomotive transformer inrush current, the process of locomotive passing through neutral section and working conditions’changing is carried out in this paper.Firstly, an appropriate short circuit capacity is selected to determine the reactance of system. Then the appropriate transformer is selected and its parameters is set. For the mode of power supply of single line NF and single line AT, based on the multi-conductor transmission line theory, the simulation model of the traction network is build. With the simulation model of CRH5, the voltage of traction transformer both at the primary side and secondary side is simulated when the traction load is switched.Secondly, then the phenomenon of magnetizing inrush current of saturated transformer is simulated, the impact factor of transformer magnetizing inrush current is analyzed, and the impact of transformer inrush current on power system is also researched.Next, the process of locomotive passing through neutral section is simulated. The model of neutral section is established, combines with the traction network model, the model of the process is established. Research on the voltage of neutral section and traction transformer is carried out, the relevant conclusions is stated.Finally, the process in which the locomotive’ working conditions changes from conditions to regenerative braking conditions is simulated. The model of working conditions’changing is build, the voltage and current of traction network and locomotive is researched, the simulation results is analyzed.