Research Based On DSP Of Switched Reluctance Motor Direct Torque Control System

The structure of switched reluctance motor(SRM)is very simple,without winding on the rotor which makes its cost very low.It is very suitable for high temperature or high speed.It has been applied to electric cars,aircraft and ship propulsion systems with very good results.However,the special double salient pole structure of switched reluctance motor causes the high saturation of the magnetic circuit at run time.Electromagnetic torque is a nonlinear function of stator current and rotor position angle with the power supply of the switch form,causing torque ripple more seriously than that of other motor systems which directly affect the output characteristics of switched reluctance motor.Thus,the noise and speed fluctuation caused by that limit its application.In this paper,a new SRM direct torque control strategy based on space voltage vector is proposed through the analysis of the principle and operation characteristics.In this paper,the current development of switched reluctance motor and the domestic and international research on reducing torque ripple are introduced.Based on the analysis of SRM working principle and mathematical model,using Ansoft software to carry out 2d finite element simulation calculation of 12/8 pole prototype,the static characteristic curve of its magnetic chain,torque and other parameters are obtained.A nonlinear simulation model of SRM is built in MATLAB/Simulink.The causes of SRM torque ripple are analyzed and the simulation model of switched reluctance motor control system under direct torque control is established.Through simulation,the control effect of the direct torque control of the traditional direct torque control and the improved direct torque control is compared,which verified that the improved direct torque control proposed in this paper can basically eliminate the torque control phenomenon and reduce torque ripple during phase change.The simulation waveforms of direct torque control and current chopper control arecompared,which verified the feasibility of improving the direct torque control to reduce torque ripple in the control system of switched reluctance motor.With DSP as the control core,the experimental platform is more secure and reliable through reasonable hardware design and software design,which provides a good foundation for the implementation of SRM direct torque control strategy.Finally,the experimental platform is set up,and the current and position waveforms are obtained through experiments.Through the experimental test of direct torque control,it is proved that the improved direct torque control has good effect on improving torque control and reducing the torque ripple of SRM.