Research On Modelless Sliding Mode Control Of Permanent Magnet Synchronous Motor

Permanent magnet synchronous motor(PMSM)has the advantages of high efficiency,fast response speed and simple structure,so it is widely used in electric vehicles,robotics,aerospace and other fields.In view of the nonlinear,strong coupling and multi-variable characteristics of permanent magnet synchronous motor,the main research contents carried out in this paper are as follows,in order to improve the robustness of the whole life cycle operation and the dynamic quality of the motor:Aiming at chattering problem of sliding mode control,an improved exponential reaching law is proposed,and a sliding mode variable structure controller based on the improved exponential reaching law is designed.The stability of this method is verified by using Lyapunov’s stability principle.Finally,a comparison experiment is done with PI control.The simulation results show that the improved exponential reaching law has faster response speed and better chattering suppression performance under different given speed conditions.When the permanent magnet synchronous motor is running in the whole life cycle,the control strategy based on the traditional permanent magnet synchronous motor model is difficult to ensure the control accuracy of the permanent magnet synchronous motor due to the complex operating conditions,mechanical wear,unknown nonlinear unmodeled dynamic control and other factors.To solve this problem,(Model-free sliding mode control,MFSMC)is proposed.First,the mathematical Model of permanent magnet synchronous motor is established considering the uncertainty of motor parameters.According to the mathematical model of permanent magnet synchronous motor under parameter perturbation,the super local model of permanent magnet synchronous motor based on system input and output is established.Secondly,a model-free non-singular terminal sliding mode control method for permanent magnet synchronous motor speed ring is proposed.A model-free sliding mode controller for permanent magnet synchronous motor speed ring is designed by using non-singular sliding mode surface and model-free control idea.Finally,in order to verify the effectiveness of the algorithm,a hardware-in-the-loop test platform was built,and simulation experiments were conducted to verify that the proposed model-free sliding mode control method can effectively improve the anti-interference performance of the system,reduce the rotational speed fluctuation of the system and accelerate the response speed of the system.