Research On Speed Control System Of Permanent Magnet Synchronous Motor Based On Weak Magnetic Control

Permanent magnet synchronous motor(PMSM)has small size,high efficiency,high power density,simple structure,and saves more energy.So PMSM is widely used in the fields of industry,transportation,military,aviation and so on.In the driving system of adopting the voltage source inverter,the essence of weak magnetic control is when the motor terminal voltage increased to the maximum of the direct inverter output voltage allowed,take steps to weaken the magnetic field intensity to meet the operating in the wide speed range.Because the research of PMSM weak magnetic control can better exert the efficiency of the motor,it has been an important subject in the research field.In the research of the weak magnetic control system of PMSM in direct torque control,when the speed and load changes,the disturbance will have a certain impact on the motor.Corresponding research is done to decrease the disturbance.The system response of DTC is fast,but it generates large torque ripple.FCS-MPC(Finite Control Set Model Predictive Control)is an emerging control concept in recent years.It has received significant attention from electrical drive community.FCS-MPC has strong ability to cope with system constraints and the torque ripple in FCS-MPC system is smaller than that in DTC system.The main contents are below:(1)In the literature research,several control methods of PMSM at present have been summarized,and advantages and disadvantages of each method have been introduced in details.Combined with the characteristics of the PMSM structure,FCS-MPC method has been proposed(2)Several coordinate transformation methods of PMSM,and the basic principle and several control methods of PMSM are analyzed.The advantages and disadvantages of each kind of weak magnetic control mode are analyzed in details.(3)When the load changes in the process of weak magnetic speed rise,adopting MPC(Model Predictive Control)control system combined with weak magnetic control method in DTC(Direct Torque Control)control system can better decrease the interference effect.Combining this two ways,the system is established in Matlab/Simulink,and the results of the system were compared and analyzed.(4)The speed change of PMSM is regarded as a kind of disturbance generated by PMSM.ADRC(Active Disturbances Rejection Controller)speed controller can reduce the interference of PMSM speed change.The PMSM weak magnetic control system based on ADRC speed control in MPC is designed,and the system simulation model is established under MATLAB/SIMULINK.The effect of PI controller and the effect of ADRC controller of the weak magnetic control system have been compared and analysised.The effect of these two different controller used in MPC control system have also been compared and analysed in detail.The simulation results show that the PMSM weak magnetic control system based on ADRC speed controller has better robustness when the speed and load change in MPC.