Research On Control Strategy Optimization Of Permanent Magnet Synchronous Motor

Permanent magnet synchronous motor(PMSM)has been widely used in aerospace,marine electric propulsion,processing center,white household appliances,automobile and industrial automation and many other fields due to its advantages of high power density,high efficiency and small torque ripple.Many key problems of permanent magnet synchronous motor have also attracted researchers' attention,such as the reliable identification of motor parameters,the mechanism of torque ripple and its suppression strategy,and the reliable operation of sensorless PMSM,which are increasingly becoming a research hotspot.Firstly,this paper summarizes the research status of different drive control strategies of permanent magnet synchronous motor.According to the magnetic field orientation mode,it classifies the drive methods and control strategies of permanent magnet synchronous motor,and summarizes the key research points of the optimization methods and control strategies.In the main part,permanent magnet synchronous motor is taken as the research object to improve the dynamic response and steady-state accuracy of speed control strategy.The influence of traditional vector control strategy,direct torque control strategy,current predictive control based on traditional control strategy and direct torque space vector pulse width modulation technology on driving effect is studied.The response process of motor with different control algorithms is explored by means of simulation and experiment.According to the simulation results,the advantages and disadvantages of different control strategies are analyzed.The dynamic response process and steady-state energy-saving height of different strategies are compared,and the characteristics of switching frequency,calculation speed and current harmonics are also taken into account.On the basis of rotor flux orientation,three control strategies,traditional vector control,single vector predictive current control and deadbeat predictive current control,are compared and analyzed.The key problems such as the establishment of PMSM prediction model,the implementation process of control strategy and the compensation of rotor position deviation are deeply analyzed.In the stator flux orientation method,compared with the traditional direct torque control and stator flux orientation voltage space vector pulse width modulation strategy.The relationship between electromagnetic torque and load angle,flux estimation method of permanent magnet synchronous motor and implementation process of stator flux-oriented voltage space vector pulse width modulation strategy are analyzed in detail.Finally,the experimental platform of permanent magnet synchronous motor is built with DSP.The design and selection of sampling circuit,signal process circuit,driving circuit and braking resistance are explained.The parameters of the experimental prototype,such as inductance,flux linkage and moment of inertia,are measured offline.The vector control algorithm,direct torque control calculation and DTC-SVM algorithm are implemented on the hardware platform.Design and debugging of the method and single vector predictive current control algorithm.The response process of the inner and outer loop of the double closed-loop system,the observational results of the torque flux linkage and the characteristic output of each control algorithm are tested.The transition process of starting,reversing,loading and unloading of the system is tested comprehensively,and the correctness of the control strategy is verified.