Abstract
Recently, the output regulation approach has been successfully applied to the speed tracking and disturbance rejection of a permanent magnet synchronous motor (PMSM). Although excellent speed tracking performance can be achieved under parameter uncertainties and unknown time‐varying load torque disturbance, the frequency of the load torque disturbance should be known. To remove such a limitation, this paper further studies an adaptive output regulation problem (ORP) of the PMSM speed servo system under time‐varying load torque disturbance with unknown frequency. An internal model‐based adaptive speed control method is proposed, which can achieve high‐precision speed tracking of PMSM under parameter uncertainties and time‐varying load torque disturbance with unknown frequency. Moreover, the convergence condition of the estimated parameter vector is given. Both the simulation and experimental results validate its effectiveness.