Study On Regenerative Braking Failure Of High-Speed Train And Its Solution

As an important part of high-speed railway,traction power supply system's safe and reliable operation is great important for high-speed railway's safe and stable operation.Highspeed trains generally adopt AC-DC-AC electric traction,which provides the necessary conditions of regenerative braking.Regenerative braking technology can not only provide sufficient braking force for trains,but also reduce the energy consumption of train operation,which is an effective braking mode.However,regenerative braking will cause traction network voltage to rise.When the voltage exceeds the maximum value of train,it will lead to regenerative braking failure,which will be a potential safety hazard.The research on regenerative braking failure of high-speed train is of great significance to make full use of regenerative braking energy and ensure the high-speed railway's safe and stable operation.The main work of this paper is to develop the solutions of regenerative braking failure of high-speed train on the basis of theoretical analysis.In order to verify the effect of those solutions,the simulation models of traction calculation and power flow calculation are built.First,the mathematical model of traction power supply system and the composition and characteristics of compound braking system of high-speed train are introduced.Then,the influences of regenerative braking on traction transformers and traction network voltage are analyzed,and the voltage loss formulas of traction transformer and traction network considering regenerative braking are given.The reasons causing regenerative braking failure include regenerative braking power,train power factor,equivalent impedance of traction network,operation organization mode of high-speed trains and voltage quality of external power system.At the same time,some solutions of regenerative braking failure are developed in this paper,including reasonable power supply mode of traction network,paralleling reactance compensation device and combined co-phase power supply system.Besides,the simulation models of traction calculation and power flow calculation of traction power supply system are established,and the simulation analysis of a practical line considering regenerative braking is carried out by using MATLAB program.Finally,the effects of solutions to restrain the regenerative braking failure are simulated and analyzed.The results show that all the proposed solutions can improve the voltage level of traction network in different extent,which demonstrate the effectiveness of solutions.