Research And Implementation Of PMSM In Anti-disturbance Control Based On Load Torque Observer

A simple PI speed control strategy has poor performance under load disturbance, when PMSM(Permanent Magnet Synchronous Motor) applied in variable and unpredictable load fields. A novel control strategy was proposed. The new strategy takes the directly measured corner and current as the known observe objects to observe the load torque, and proportionally feedforward to the PI speed regulator to weaken the influence of load disturbance and achieve adaptive disturbance rejection of PI control. This method provides a certain level of theoretical exploration and practical solution.Through rigorous theoretical derivation, a control calculation method of the proposed control strategy is obtained, built a theoretical model in simulink, and the simulation verified the correctness of the reduced-order load torque observer design method. The load torque observed by simulation responses fast without overshoot. But also verified the feedforward strategy has better anti-disturbance performance caused by load changes, smaller speed fluctuation, less adjustment time and better robust performance realtive to the simple PI strategy through the model simulation.The thesis built a PMSM drive controller debugging platform with the designed drive board and control board. The experiments on the debugging platform verified the correctness of the observer design strategy, and designed the software filter to reduce the load torque fluctuation and enhance the availability of obseved value of the load torque. Comparative analysised the control performance of the load torque feedforward PI speed regulator and the simple PI speed regulator, and verified that the feedforward strategy has better steady precision under the sustained load action, less overshoot under discontinuous load and better anti-disturbance performance with the same PI parameters.