Torque ripple minimization in dual inverter open-end winding PMSM drives with non-sinusoidal back-EMFs by harmonic current suppression

摘要

This paper presents a closed-loop control strategy for dual inverter-fed, permanent magnet synchronous motors (PMSM) with non-sinusoidal back electromotive force (back-EMF). The inverters are connected to both ends of the machine winding but use only one power source, thus providing a path for zero sequence currents to circulate in the motor windings. Due to the non-sinusoidal back-EMFs and circulation of zero sequence currents, the machine electrical torque is now a function of the rotor position that leads to torque ripple oscillations. Therefore, a closed-loop control strategy to suppress the circulation of zero sequence currents and amplitude of the dominant current harmonics caused by the non-sinusoidal back-EMFs is developed and demonstrated by experiment. The zero sequence component is considered as one additional degree of freedom that has to be managed. Therefore, the control scheme to regulate the ac signals in the regulators is developed and an approach to minimizing the torque ripples is presented.