Research On Model-free Sliding Mode Control Of Permanent Magnet Synchronous Motor

As the core component of the drive system,permanent magnet synchronous motor(PMSM)is widely used in industrial production,aviation and other fields.Due to it faces various complicated and varied environments and operating conditions,and its resistance,inductance and other parameters are vulnerable,and the permanent magnet of PMSM has a problem of demagnetization,the performance of PMSM have been greatly affecting.Most of the existing control methods for PMSM are based on the ideal mathematical model of the motor to design the controller.In order to reduce the dependence of the controller on the specific model of the system,and improved the robustness of the controller,the model-free sliding mode control method of PMSM is reserched in this paper.The main contents of this paper are as follows:Aiming at the problem of nonlinear and strongly coupled of PMSM control system,a model-free sliding mode control method based on sliding mode observer is proposed to improve speed response of motor.Firstly,an ultra-local model is established based on the input and output of speed to design a model-free sliding mode controller.Then,a sliding mode observer is designed based on the ultra-local model to estimate the unknown terms in the ultra-local model.Finally,the feasibility of the method is verified by simulation.Compared with the sliding mode control method,the results demonstrate that the model-free sliding mode control method has faster response of speed and robustness.Aiming at the instability of motor control caused by the uncertainty of parameters of PMSM,a model-free sliding mode control method based on ultra-local model is proposed.Firstly,considering the uncertainty of the motor parameters,a mathematical model of the d-q coordinate system is established,and the ultra-local model of speed cloop is established.Then,a model-free sliding mode controller for IPMSM speed loop based on ultra-local model is designed,and the unknown parts of ultra-local model are estimated by sliding mode observer.Finally,compared with IPMSM vector control system controlled by PI,the simulation and experiment results show that the proposed method is robust to the motor parameter uncertainty.A robust model-free nonsingular terminal sliding mode control(MFNTSMC)algorithm based on the ultra-local model is proposed for PMSM,which can reduce the influence of permanent magnet demagnetization and external disturbances.First,the ultra-local model are constructed based on the input and the output of speed loop and current loops in PMSM vector control system.Secondly,the model-free nonsingular terminal sliding mode controller that used to control speed and current is designed based on ultra-local model.Then,the sliding mode observer(SMO)is designed to estimate the unknown terms of the ultra-local model.Finally,the proposed scheme was simulated using Matlab/Similink and implemented on the RT-Lab platform,the effectiveness of the proposed scheme is verified.Compared with the PI control method,the results verify that the proposed scheme is able to improve the dynamic response speed and enhance robustness of PMSM control system.