The Research Of Special Vehicle High-power Permanent Magnet Synchronous Drive System

With the zero-emission electric vehicle pollution,high energy efficiency,good mechanical control performance and many other advantages,electric cars to get people's attention.coupled with today's global energy shortage,global warming and our show persistent haze pollution problems,make electric cars become a branch of the fastest growing automotive sector.Combined task requires,this paper studied electric vehicle motor drive system.Firstly,analyzed the current status of the development of electric vehicles,and used in a variety of motors for electric vehicles are classified comparison,the built-in high-frequency high-power permanent magnet synchronous motor drive system for electric vehicles superiority.Through the establishment and analysis of interior permanent magnet synchronous motor mathematical model is proposed maximum torque current ratio control segment fitting optimization methods and weakening expansion velocity theory,improved control accuracy.Through the establishment of MATLAB simulation for the text,the proposed method is validated.Secondly,according to the high-speed high-power electric vehicle operational requirements,describes the significance of enhancing carrier ratio describes the switching losses of semiconductor devices and soft-switching technology;raised by raising the motor back EMF space vector modulation approach taken to improve the inverter bus methods to reduce the load current utilization,thereby reducing switching losses;studied vector modulation techniques five-phase modulation and seven-segment modulation method,to improve the system than in the switching frequency of the carrier unchanged,to control the effect of improving purpose and simulation to verify the feasibility of this method.In addition,to improve the high-frequency carrier frequency is too low to control conditions caused by the problem of declining performance,this paper proposes a novel current control strategy.High-speed operation of the motor,through a transient current corrector motor dq axis current reallocated in order to achieve the purpose of improving the performance of the current control loop.This paper validate the superiority of the current regulator by simulation and experiment.Finally,designed the part of the electric vehicle drive system hardware and described the software control flow chart in detail,build a TMS320f28335 experimental platform for the master chip.In Xiang Tan Electrical Machinery Plant had finished a series of experiments for electric vehicle drive system under different conditions at different load and different speed.Experimental results demonstrate the feasibility of this method and the proposed method has application prospect.