Research On Nonlinear Internal Model Based Position Control Algorithm Of Permanent Magnet Synchronous Motor And Its Digital Implementation

Permanent magnet synchronous motor(PMSM)has been widely used in various industrial applications such as electrical vehicle,robot and numerical control machine tool due to its simple structure,high power density,high efficiency and fast dynamics.Since PMSM is a complicated multi-input,multi-output nonlinear system affected by both load torque disturbances and parameter uncertainties,it is difficult to achieve a high precision position control of PMSM by classical PID control method.Nevertheless,robust output regulation theory can achieve multiple goals including trajectory tracking,disturbance rejection and parameter robustness simultaneously.Thus,it is significant to study the position control problem of PMSM by robust output regulation theory.This thesis mainly studies the position tracking and nonlinear disturbance rejection problem of PMSM and also presents the digital implementation of the proposed two position control algorithms.The main research work is as follows:(1)This thesis studies a local position tracking and nonlinear disturbance rejection problem of PMSM.This problem can be formulated as a robust output regulation problem of multivariable nonlinear systems.A nonlinear internal model based output feedback control law is proposed,which can achieve asymptotic tracking of desired position and reject nonlinear external disturbances in the load torque.Simulation results demonstrate the effectiveness and superiority of our design.(2)This thesis studies a position tracking and nonlinear disturbance rejection problem of PMSM with wide position range.A two-step controller design strategy is proposed,which can achieve position tracking and nonlinear disturbance rejection of PMSM with wide position range.This strategy combines the advantages of classical triple-loop control and nonlinear internal model control.First,triple-loop control is adopted to regulate the rotor position to the neighborhood of the reference position.Second,nonlinear internal model control is adopted to regulate the position tracking error to zero asymptotically.Simulation results demonstrate the effectiveness and superiority of our design.(3)Experimental studies of the proposed two position control algorithms are carried out by PMSM experimental setup.Compared with the classical triple-loop control method,the above two position control algorithms can achieve high precision position tracking control of PMSM subject to both nonlinear load torque disturbances and certain parameter uncertainties.This research first presents experimental results of the robust output regulation problem for the PMSM servo system,which demonstrates the effectiveness of nonlinear internal model control technique in real-time experimental setup and bridges the gap between the output regulation theory and real applications.