Research And Development Of PMSM Servo System Based On Auto-disturbances Rejection Controller Techniques

Permanent Magnet Synchronous Motors (PMSM) have numerous inherent advantages over other machines that are conventionally used for AC servo drives. High efficiency, high power density (kw/kg) and high torque to inertia ratio are some of the PMSM characteristics responsible for its wide utilization in different domains. In this dissertation, speed and position estimation, speed and position tracking, friction compensation and other key problems of speed sensorless PMSM servo drive are investigated in detail. And based on those, a novel approach for speed sensorless PMSM servo drive system is presented.Based on Active Disturbance Rejection Controller (ADRC) techniques, a novel rotor speed and position estimation strategy to sensorless PMSM servo drive is presented in this dissertation. In the strategy, the rotor speed and d-axis current in q-axis current loop are regarded as cross-coupling item, which is observed by ADRC and then the rotor speed is estimated from the cross-coupling item. Simulation and experimental results show that the rotor speed and position can be accurately estimated from 0r/min to 2000r/min, and the PMSM servo system has strongly robust to load disturbance.In order to restrain the disturbances in PMSM servo drive caused by the changes of load, friction and rotor inertia, a speed control method based on ADRC techniques is presented in this dissertation and the speed ADRC model is also proposed. Based on ADRC, these parameter changes are regarded as disturbances of speed loop in PMSM servo system, which are estimated and then compensated by speed ADRC. Simulation results show that the servo system robust to those disturbances from 0r/min to 2000r/min, and the friction torque is compensated by the control method.A position control approach based on ADRC techniques is also presented in this dissertation. Aim at the speediness, accuracy and overshootless of position control, as well as the restrain of disturbance, a transitional process is arranged for the given position by the Tracking Differentiator (TD) of ADRC, and the disturbance effects upon position control is also observed and then compensated by the Extended State Observer (ESO) of ADRC. Simulation results show that the servo system robust to stator resistance, rotor inertia changes and load disturbance. When given position is 100rad and 0.1sin( 2Ï€t)rad, the steady state error is 0.033rad and 0.00038rad, respectively.Grounded on the work above, a real system includes TI's DSP TMS320LF2407A as central control unit is developed, and the monitor control system based on Controller Area Network (CAN) bus is designed.