Permanent Magnet Synchronous Motor Control Based On Sliding Mode Disturbance Observer

Permanent magnet synchronous motor(PMSM)has the advantages of light weight,low noise,high power density,simple structure,etc.,and is widely used in industry.However,the permanent magnet synchronous motor is a typical nonlinear and strongly coupled system,and the motor parameters are easily changed by internal and external influences.Conventional PI control is difficult to meet the current industrial control precision and demand.In order to effectively improve the robustness and control accuracy of the permanent magnet synchronous motor control system,this thesis establishes a permanent magnet synchronous motor mathematical simulation model,combines sliding mode control theory and disturbance observer technology,and effectively improves the control performance of the permanent magnet synchronous motor.The main research contents of this thesis are as follows:Considering that chattering defects of traditional sliding mode control,a piecewise power reaching law control method is proposed on the basis of existing research.The traditional approaching law is difficult to weaken the chattering in the minimizing approaching stage.A segmented power approaching law is designed.The first stage adopts the conventional approaching law to ensure that the sliding mode surface can be reached within a finite time.An auxiliary linear term is added after the second power term to better suppress chattering.The problem of the conflict between the convergence speed and sliding mode chattering in the traditional reaching law is solved.For the solving of various disturbances during the motor operation,including model uncertainty disturbances,external load disturbances,etc.,a method based on sliding mode disturbance observer combined with motor inertia identification is used to observe and compensate for disturbances.First,a sliding mode disturbance observer is designed with the load torque and speed as state variables,and the observation results are fed back to the speed control loop;then the model reference adaptive algorithm is introduced to identify the motor moment of inertia online;finally,the identification The results are updated to the observer and the speed loop controller to achieve the purpose of improving the performance of the control system.Simulation Model of Permanent Magnet Synchronous Motor Control System is developed by Matlab/simulink,and compare PI control,sliding mode control and compound control strategies.Simulation and experimental results show that,compared with the traditional PI and conventional sliding mode control,the new sliding mode control combined with the disturbance observer control strategy has better performance and better robustness,which improves the dynamic and static performance of the system.With the TMS320F28335 microprocessor as the center and the motor software and hardware control system as the basis,the permanent magnet synchronous motor servo control system is constructed,and the design of the main software and hardware circuits is designed to verify the feasibility and correctness of the control method.