Research And Implementation Of Speed Control Method For Switch Reluctance Motor Of Electric Vehicle

Switched Reluctance Motors(SRM) as a new generation speed control motor,it has been favored by researchers since its inception.Its main advantage are simple and strong structure,wide speed range, high starting torque, high efficiency, low price.Switched Reluctance Motor Drive(SRD) speed control system has good speed performance,flexible control,it can meet the complex operational requirements of electric vehicles.But SRM’s structure and highly nonlinear characteristics lead to great torque ripple.So we need sophisticated algorithms to complete the precise control of SRM and minimization the torque ripple.To solve this problem, this paper puts forward the comprehensive control strategy : the PI parameter self-adaptation of speed and current double closed loop control mode based on cosine type torque distribution function combining with the fuzzy turn-on and turn-off angle optimization to suppress the torque ripple. The main work is as follows:First, this paper analyses the reasons of torque ripple and the effect on torque ripple of turn-on angle and turn-off angle optimization, The simulation results show that the change of the switching angle can restrain the torque ripple. Considering the nonlinear characteristics of SRM,this paper adopt fuzzy control which is not depend on the mathematical model to optimize the turn-on angle and turn-off angle.During the commutation, to the problem of excessive torque ripple,this paper adopts torque distribution function and analysis the different torque distribution function,The final best choice is cosine torque distribution function.Due to the slow response of SRM at low speed start, the torque ripple is very large,the method PI parameter self-adaptation is adopted.It is double closed-loop system with the speed and current.This paper completed the design of speed regulator and current regulator and calculated their PI parameters.Finally simulation study to this system is completed in MATLAB.This paper finally builds the hardware platform of SRM and completes the hardware circuit design with dsPIC33FJ32MC204 as the control core. Based on the hardware design platform, the part of software is designed..Comprehensive comparison between the simulation results and the experimental results, the control method in thispaper can suppress the torque ripple, the system has good speed regulation performance.