A novel modular 4-level power converter-based direct instantaneous torque control strategy for switched reluctance machine

The direct instantaneous torque control strategy for switched reluctance machine with a novel modular 4-level power converter is proposed in this paper. Compared with the modular 3-level converter, the proposed modular 4-level converter has an additional charge capacitor, diode and power switch. By using this new converter topology, the direct instantaneous torque control strategy can breakthrough the voltage limitation of the modular 3-level converter and accelerate the magnetization and demagnetization process, which significantly helps to decrease the torque ripple and improve the dynamic performance of the SRM. The direct instantaneous torque control strategy corresponding to the 4-level power converter is described and analyzed in different conduction regions in detail. The effectiveness of the proposed converter and control strategy is verified by simulation with a 1kW three-phase 12/8-pole SRM prototype.