Reconfigurable Modular Fault-Tolerant Converter Topology for Switched Reluctance Motors

Abstract

Switched reluctance motors can be driven in a conventional or a modular way. In the conventional driving method, a number of stator coils are connected together and driven from one converter module. In the modular driving method, each stator coil is driven from one separate converter module. The conventional driving method provides better drive performance (i.e. efficiency, torque ripple, and power density) but narrower speed range at rated torque and less fault-tolerance capability. The modular driving method provides wider speed range at rated torque and much better fault-tolerance capability. Therefore, in low speed healthy operation, the conventional driving method is preferable while for high speed and faulty condition, the modular driving method should be used. In this article, a converter topology that can be reconfigured to operate in conventional and modular driving ways is proposed and analyzed. Using the proposed converter, the benefits of the conventional and the modular driving methods can be obtained by proper configuration of the converter. Also, a fault-tolerance strategy that results in symmetrical and high-performance operation of the drive is proposed. The performance of the converter is assessed by simulations and experimental measurements.