Fractional-Order Based Resonant Controller for Torque Ripple Suppression of Permanent Magnet Synchronous Motors

Permanent magnet synchronous motor (PMSM) has been widely used in servo control system, However, due to dead effect of inverter, current measurement errors, the stator current contains some harmonic components that will result in torque ripple. To reduce the current harmonics, this paper presents a fractional-order based resonant controller (FOBR). The proposed controller is an extension of the integer-order quasi-resonant controller, with more degrees of freedom to increase the flexibility of controller regulation. The digital implementations of the proposed controller is also presented, and simulations and experiments were performed for verification. The results demonstrated that the proposed controller achieves better harmonics suppression than the integer-order quasi-resonant controller and pure PI controller.