Speed Feedforward Control Method Based on Improved Adaptive Filter for Permanent Magnet Synchronous Motor

An adaptive filter is used as the speed loop controller for permanent magnet synchronous motor (PMSM) drive system to improve the dynamic and anti-disturbance performance. The weightings of the filter are adjusted by the normalized least mean square (NLMS) filtering algorithm, so that the transfer function of the controller is equivalent to the inverse model of the controlled plant in the system. At the same time, the weightings of the filter are transferred to the speed feedforward controller in time, which makes the transfer function can approximate to the inverse model of the controlled plant. Then, the feedforward control and speed tracking are realized. In addition, a second-order extended state observer (ESO) is designed to estimate and compensate the total disturbances of the system. Simulation results verify the effectiveness of the proposed method.