Predictive control of permanent magnet synchronous motor with non-sinusoidal flux distribution for torque ripple minimisation using the recursive least square identification method

To reduce the torque ripple of permanent magnet synchronous motor with non-sinusoidal flux distribution, a new method is presented in this study. This method is based on model predictive control (MPC). MPC is a model-based control and requires an accurate model of the motor. A sliding mode observer, accompanied with a recursive least square estimator, is utilised to determine the magnitudes of the harmonics of the back electromotive force (EMF) waveforms. The appropriate current harmonics, considering the back EMF harmonics, are injected to shape the motor current. The interaction of non-sinusoidal back EMF and the shaped current leads to torque ripple reduction. The experimental results verify the effectiveness of the proposed method.