SVM-No Flux Linkage Direct Torque Control Of PMSM Based On AEKF

The permanent magnet synchronous motor(PMSM)has advantages of simple structure,high power factor,large torque inertia ratio and so on.So in the meantime,it is more and more widely used in the production and daily life.Direct torque control(DTC)makes the inverter and motor became one.DTC takes the electromagnetic torque as the direct control object.This control mode has advantages of simple control algorithm,good dynamic performance and less rely on parameters of motor.Therefore,PMSM DTC has promising application and research value.However,the PMSM DTC also has some weakness,it uses the switch table selection space voltage vector lead to a sizable torque ripple,and it uses the sensor makes the cost incurring,sensor sensitivity degradation under external environmental disturbance and so on.These problem has been solved in this paper based on the traditional direct torque control,and lead-in the sensorless control based on extended Kalman filter(EKF),and effectively improve the accuracy of the system and the dynamic and static performance of the motor,the contents of this paper are summarized as follows:Firstly,this paper summarize the research status of torque ripple suppression and speed sensorless control in domestic and abroad.Induction the mathematical model of PMSM under different coordinate systems and the transformation relationship between different coordinate systems,and discuss the principle of traditional direct torque control based on stator winding star connection,use the Matlab/Simulink analysis the function of motor under the no-load,variable load,variable speed operation mode.Secondly,the no flux linkage DTC of permanent magnet synchronous motor is derived by the formula,and compared with the traditional direct torque control by simulation analysis.It is proved that it can improve the torque response speed and reduce the torque ripple.At the same time,the space vector pulse width modulation(SVPWM)technology is applied to the no flux linkage direct torque control,this method ensures the torque response speed and reduce the torque ripple,simulation results has confirmed the superiority of the proposed control method.Besides,in order to achieve sensorless control,extended Kalman filter(EKF)is introduced into the SVM-no flux linkage direct torque control of permanent magnet synchronous motor,considering the observed effects of EKF is greatly affected by the filtering parameters,and the convergence effect is not good.This paper proposes an adaptive extended Kalman filter(AEKF)theory,and through simulation analysis,it is proved that the convergence and the observation accuracy are better.At last,according to the above theoretical analysis design the hardware and software.Build an experimental platform with TMS320F2812 as the core,introduce the composition and principle of each module of the experiment platform.With CCS3.3 as the software debugging platform,this paper introduce the main program and the flow of interrupt program of the software,all the necessary experimental verification are carried out,and the experiment results show that the theory of this paper is feasible.