A control problem of PM synchronous motor by two-step internal model controller design

Much recently, a local speed tracking and nonlinear disturbance rejection problem of PM synchronous motor was formulated as a robust output regulation problem of multivariable nonlinear system and well addressed by nonlinear internal model design. In this paper, we propose a novel two-step controller design strategy to achieve speed tracking and nonlinear disturbance rejection of PM synchronous motor with wide speed range, which combines the advantages of classical double-loop control and nonlinear internal model control. It is worth mentioning that the proposed two-step controller design strategy can not only guarantee exact speed tracking with wide speed range, but also reject small nonlinear external disturbances in the load torque, generated by a so-called nonlinear exosystem. Simulation results demonstrate the effectiveness of our design.