A control system-based reduction of electromagnetic torque ripples in a VSI-fed poly-phase PMSM with nonsinusoidal back-EMF

The paper presents a model of a permanent magnet motor with M sets of three phase stator windings energized from DC-DC and DC-AC converters and regulated by a control subsystem of the marine propulsion drive. The model is built up by decomposing the system into subsystems / sub-circuits which are coupled together via dependent voltage/current sources. The model takes into account the non-sinusoidal waveform of back-EMF and its impact on the current distortion and electromagnetic torque ripples. The paper concludes by analyzing simulation results that have shown significant suppression of the 5th order current harmonic and corresponding decrease in the torque ripples due to the proposed control algorithm.