A New Three-Level Switched Reluctance Motor Drive for Electric Vehicles

Multilevel power converters have been investigated to improve system-level performance in switched reluctance motor (SRM) drives used in low-voltage applications including electric vehicles. This paper introduces an eight-leg asymmetric three-level power converter that splits the battery into two banks to generate similar operating modes as the conventional three-level asymmetric converters but with improved performance, reduced size, and cost. Unlike the series-connected single battery bank, the proposed split-battery connection offers flexible control and fault tolerance for the SRM drives. The operating modes for the proposed converter are defined, and a current chopping control scheme is presented. The proposed split-battery-driven converter is compared with the standard two-level asymmetric half-bridge converter, and three-level asymmetric converters in terms of cost, efficiency, torque ripple, and current ripple under different operating conditions. The feasibility of the proposed topology is thoroughly tested using a three-phase 12/16 SRM model in MATLAB simulations.