Research And Realization On Convertor Control Arthmetic Of High Speed EMU At Regenerative Braking State

Braking control system is one of the key techniques in the safe running process of high speed Electrical Multiply Unit (EMU), high speed EMU adopts the regenerative braking control strategy combined with the electric air braking method. Among all the braking methods, Only can regenerative braking feedback energy to the catenary. Thus it has come to be the preferential braking mode of AC traction EUM.Based on the regenerative braking control system of high speed EMU, the thesis researchs the working characteristic, design method of control system and control strategy in detail.Firstly, the constitute and function of braking system are introduced, the principle of regenerative brake and its applying states are presented in detail. The control system of traction convertor is deeply researched when EMU is at regenerative braking state, Which include transient direct current control of the single-phase three-level PWM rectifier and indirect rotor-flux-field-oriented vector control system of three-level inverter.On the basis of principle analysis, the regenerative braking simulation system of high speed EMU is established by Matlab/Simulink, the torque and flux command are sent according to the regenerative braking trait; a constant speed controller based on double-hysteretic band adjustment is designed in order to realize the EMU's constant speed control; Through the smoothly switching strategy, the torque, flux impulsion are avoided during the switching process. Adopting high speed EMU's main circuit and parameters, the simulation results prove the simulation system well realizes the EMU's regenerative braking performance.In order to validate the three-level inverter vector control means applied to the high speed EMU, a three-level lab platform is established, the hardware and control circuits are introduced in detail, and the control system using TMS320LF2407 and TMS320VC33 is set up, the software flowchart of indirect rotor flux field oriented vector control is designed, and the three-level SVPWM is proved by experimental results.