Research On Current Predictive Control Of Permanent Magnet Synchronous Motor

With the development of permanent magnet material technology and the promotion of energy saving and emission reduction and environmental protection strategy,permanent magnet synchronous motor(PMSM)is widely used in modern industrial control due to its high efficiency,energy saving,reliable operation and many others advantages.The traditional control methods have slow dynamic response and low steady-state accuracy,so it is difficult to meet the control requirements of some high performance occasions.Therefore,it is necessary to study more advanced control methods.As an algorithm generated in industrial practice control,predictive control has good performance.This thesis mainly focuses on the predictive control of PMSM speed control system.Firstly,the mathematical model of PMSM under different coordinate systems is deduced,the principle of space voltage vector pulse width modulation(SVPWM)and vector control is expounded,and the field orientation control(FOC)system of PMSM is established.Secondly,the finite control set model predictive control(FCS-MPC)is used in the current loop of vector control,and the predictive current control system is constructed.In order to solve the problem of large current fluctuation,the duty cycle control is realized by combing the fast vector selection method,and the duty cycle is calculated according the idea of deadbeat control to obtain better torque output.On this basis,the generalized two-vector predictive control with its feedback correction is proposed to reduce current fluctuation.Considering the overall performance of the system,the speed prediction controller is designed,which can adjust the speed quickly,smoothly and without overshoot,to improve the dynamic performance of the system.Finally,The deadbeat current predictive control is used in the current loop of vector control,and the deadbeat current predictive control system of permanent magnet synchronous motor is constructed.In order to solve the problem that it is sensitive to the parameters in the controller,robust control is introduced into the deadbeat control algorithm to increase the stability range of the system.On this basis,the integral control with its anti-saturation is used to eliminate the current static error caused by parameter mismatch.The speed predictive controller is used again to further improve the control performance of deadbeat current predictive control system.