Quasi-Z-Source-Fed SRM Drive for Torque Ripple Minimization and Speed Range Extension With Three-Switch Conduction

Abstract

This paper proposes a quasi-Z-source (QZS)-based modular switched reluctance motor (SRM) drive to suppress the source current ripple, minimize the torque ripple, widen the constant torque range and speed range, and enhance the system reliability. To take full advantages of QZS unit and modular power modules, the QZS-based modular SRM converter is firstly constructed. Subsequently, a three-switch conduction-based current compensation mechanism is developed to deal with the torque plummet issue caused by the inherent series excitation mode. Meanwhile, a novel four-region DITC strategy is proposed to further suppress torque ripple. Furthermore, a voltage regulation method is developed based on compensation mechanism to suppress the source current ripple and provide great assistance to implement the above strategy more effectively. In addition, the shoot-through state can be evenly distributed among the four bridge arms, which is conducive to balance the heating dissipation of power devices for improved service life of power converter. To validate the feasibility and effectiveness, the experiments are carried out on a 150W three-phase 12/8 SRM prototype.