A Drive Topology for High-Speed SRM with Bidirectional Energy Flow and Fast Demagnetization Voltage

A drive topology composed of a T-type single-phase three-level voltage source rectifier (VSR) and a four-level switched reluctance motor (SRM) converter is proposed in this article. The commonly used diode bridge rectifier presenting degraded power quality is replaced by the VSR to drive the SRM converter. Compared with the conventional split-dc converter, the four-level SRM converter of the proposed drive topology adopts one more switch and one more diode for each phase, but two more operation modes are formed. With the double-voltage demagnetization mode of the four-level SRM converter, the tailing time of demagnetization current is significantly reduced, which increases the utilization of inductance increasing region. All the operation modes of this converter can be implemented successfully, even in the multiphase excitation region. Moreover, a centralized control strategy is proposed to regulate the VSR and SRM together, within which the speed and grid-side power factor are regulated by the d-axis and q-axis component of grid-side current in VSR, respectively. Most importantly, the bidirectional energy flow is realized. An idea-proofed testbench is constructed. The results obtained from the comparative experiments confirm the validity of the proposed drive topology and its control strategy.