Permanent Magnet Synchronous Motor Speed Control Method with Fractional Order Disturbance Observer

In this paper, a permanent magnet synchronous motor (PMSM) fractional order (FO) speed control method with FO disturbance observer is proposed. On the basis of PMSM vector control, a fractional order PI (FOPI) speed controller is designed. The FOPI parameters are tuned through speed open loop gain crossover frequency specification, phase margin specification and ITSE optimization to load torque step. To suppress the load torque disturbance further, a fractional order disturbance observer (FO-DO) is established. Through ITAE optimization, higher indiscrimination degree is achieved than integer order type-II system. Lastly, the effectiveness of the proposed method is verified on a MATLAB based PMSM control simulation platform. Higher tracking precision and better disturbance rejection can be achieved through the FOPI plus FO-DO control method.