Modular Seven-Leg Switched Reluctance Motor Drive With Flexible Winding Configuration and Fault-Tolerant Capability

This article proposes a modular seven-leg switched reluctance motor (SRM) drive with a flexible winding configuration and fault-tolerant capability. In traditional SRM drives, the winding connection is fixed, where the speed regulation range and fault-tolerant ability are both limited. To solve these issues, a modular seven-leg drive topology is proposed, where each phase winding is divided into two segments, and the winding connection can be flexibly switched to achieve a wide speed range. At low speed, the winding segments are connected in series for a higher output torque, while the parallel connection is employed at high speed to extend the speed range. In addition, a swift and smooth online winding switching process is achieved, where there are no current or speed shocks. Furthermore, owing to the flexible winding connection in the proposed topology, effective fault-tolerant strategies are developed to deal with the open-circuit faults in both series and parallel connections, which can maintain the output capability and avoid large torque ripples when open-circuit faults occur. Meanwhile, the proposed drive topology is constructed by commercial half-bridge modules and is suitable for industrial applications. Simulations and experiments are carried out on a three-phase SRM prototype to verify the feasibility of the proposed scheme.