Robust control methods for PM synchronous motor

Robust controllers which are designed by employing discrete-time reaching law control (RLC) and internal-model control (IMC) are presented for permanent magnet synchronous motor (PMSM). They are to achieve accurate control performance in the presence of uncertainties and plant parameter variation. As the powerful technique to control the nonlinear and uncertain systems, IMC is applied to PMSM current control. The synchronous-frame PI-type IMC controller greatly improves the performances of the current loop and simplifies the design procedure. The RLC-based speed controller is proposed, and the design equations are derived in the discrete time since the discrete time analysis and design is more appropriate for the digital control applications. The robustness of RLC-based speed controller is analyzed, and the bounds of control parameters that ensure the drive stable are obtained. Simulation results verify the proposed control methods for PMSM.