Research On The Speed Regulation System Of Permanent Magnet Synchronous Motor Based On Adaptive Terminal Sliding Mode Control

In recent years,with the development of AC motor structure and control theory,AC speed regulation has gradually become the main development direction of speed regulation drive systems.Permanent magnet synchronous motors(PMSM),as one of the executive components of AC speed regulation systems,are widely used in domestic appliances,industrial production,high-end equipment,national defense construction and other fields because of its characteristic of small size,simple structure,high efficiency and reliability.However,PMSM is a complex nonlinear system which has the characteristics of multivariable and strong coupling.While its motor parameters are easily disturbed by temperature and magnetic saturation,which resulted the motor speed control system rarely meet the expected performance.In order to optimize the performance of PMSM speed regulation,adaptive algorithm is combined with terminal sliding mode control theory and utilized to perform the following research in this paper:Firstly,the basic structure of PMSM and the coordinate transformation theory in vector control are introduced,and the mathematical model of surface mounted PMSM is established.On this foundation,the simulation model of PMSM speed regulation system and the experimental test platform are established.The traditional PI algorithm is used to perform the current loop and speed loop control of the speed regulation system,and the relevant simulation and experiments are completed on the built platform.Analysis results verified the effectiveness of the designed platform and applied the foundation for subsequent research.Secondly,the sliding mode control theory is briefly introduced,and its application in the PMSM control system is analyzed.Based on the theory of sliding mode control,the traditional sliding mode controller is designed as the speed loop controller in the double closed-loop control system of PMSM.In order to improve the convergence and disturbance rejection performance of traditional sliding mode controllers,a new speed loop controller is designed by introducing nonsingular terminal sliding mode surface and combined with terminal sliding mode control principle.The control performance of different control methods under the condition of no-load starting and variable load is compared and analyzed.Simulation and experimental results confirmed that the terminal sliding mode controller has a performance of faster convergence speed,smaller overshoot and stronger anti-interference compared with PI and traditional sliding mode control.Finally,a new adaptive terminal sliding mode control method is proposed for the problem that the terminal sliding mode control method unable to enhance the antiinterference ability of the system and weaken the chattering simultaneously.The new speed loop controller which combined the adaptive law and the terminal sliding mode control algorithm is designed,in which the switching gain can be changed according to the change of the system disturbance.The adaptive terminal sliding mode controller can automatically select the minimum gain which is consistent with the system stability to reduce the system chattering without reducing the disturbance immunity of the system.The simulation and experimental results verify the effectiveness of the adaptive terminal sliding mode control method,and achieve the purpose of adaptive law design.