Research On Vector Control System Of Asynchronous Motor For Electric Vehicles

As the increasingly serious problem of environment pollution and energy crisis,the development of electric vehicle has become a popular direction of car research due to its quality of zero-emission and energy-efficient.Motor drive system of electric vehicle is the core part of EV,asynchronous motor is widely used in EV(especially in low-speed EV)since its low-price,simpler construction and better reliability.At present,the realization of asynchronous motor drive is mainly based on rotor flux-oriented control and speed,current double closed-loop,and current loop mainly adopt PI regulator.But traditional PI regulation has its inherent characteristics of hysteresis,it may bring an effect on the tracking performance of torque current and dynamic response of EV.In order to improve this influence,this paper presents an vector control method based on current prediction for EV,builds related simulation model of Simulink and develops a motor controller sample machine based on TMS320F28035.Simulation and experimental results show that vector control based on current predictive control has better effectivity.Firstly,this paper introduces the working principle of asynchronous,analyzes the transformation of coordinates and asynchronous motor model in different coordinates and introduces the theory of Space Vector Pulse Width Modulation(SVPWM)and block diagram of asynchronous vector control.In order to guarantee the accuracy of vector control,this paper research the method of flux observing and identification of motor parameter.Then,this paper analyzes the concept and disadvantage concept of PI regulator,presents an vector control method based on current predictive algorithm,and builds related simulation model.Simulation results show that current predictive control can predict the control order of next period in this period,which can improve the dynamic response effectively.Finally,software and hardware of motor controller sample machine based on TMS320F28035 are designed on the basis of theory analysis,this paper builds the experimental platform,and finish the experiment of motor parameter identification.Road test is conducted at the same time.Data of road-test shows that vector control based on current predictive control has better effectivity and can make the EV steady.