Composite Sliding Mode Controller Design For PMSM Speed Regulation System Based On A Novel Disturbance Observer

AC servo motor control system has been an essential branch of the automatic control system,due to the development of new technology and automatic control theory.Permanent magnet synchronous motor(PMSM)has been widely used in many areas,such as numerical control machine tool,aerospace,robots and various military equipment because of its high magnetic density,high efficiency,big torque-inertia ratio and small torque pulse.In recent years,the AC servo motor control based on permanent magnet synchronous motor(PMSM)has become a research hotspot in the field of motor control.However,permanent magnet synchronous motor is a complex system with strong coupling and non-linearity.In order to effectively improve the ability of antidisturbance and robustness of PMSM control system and reduce the influence of timevarying parameters and interference.In this paper,sliding mode control theory and disturbance observer technology are used to improve the control performance of permanent magnet synchronous motor speed control system.Firstly,the mathematical model of PMSM in the rotating coordinate system is established and the main algorithms of PMSM servo system are introduced and analyzed.The vector control simulation model of PMSM based on traditional proportional integral controller is built in MATLAB software.The experimental platform of PMSM servo system is built and the corresponding program is compiled.At the same time,the hardware circuit principle of the experimental platform is briefly analyzed.Secondly,the principle of sliding mode variable structure control is briefly introduced and analyzed.Then,the conventional sliding mode controller for speed-loop of permanent magnet synchronous motor control system is given and the simulation and experimental results of the controller are given.In order to further improve the performance of the sliding mode controller,this paper applies the super-twisting controller to the permanent magnet synchronous motor control system.The simulation and experimental results verify the superiority of the super-twisting controller.Then,the traditional disturbance observer is realized by taking the permanent magnet synchronous motor control system as the controlled object.On this basis,a new disturbance observer theory is proposed in this paper.The first-order and second-order disturbance observers of the permanent magnet synchronous motor control system are deduced by using the theory,and the simulation and experiment are carried out.The simulation and experimental results show that the performance of the new disturbance observer can effectively observe disturbances in the PMSM control system.Finally,in order to further improve the ability of anti-disturbance of the supertwisting controller and reduce the switching gain of the super-twisting controller,the novel first-order disturbance observer and super-twisting controller are combined to construct a composite controller of the permanent magnet synchronous motor control system.The simulation and experimental results show that the method of super-twisting sliding mode control combined with disturbance compensation technology has better anti-disturbance ability,and attains expected control effect.