An Asymmetric Three-Level T-Type Converter for Switched Reluctance Motor Drives in Hybrid Electric Vehicles

This paper introduces a 3-level converter for switched reluctance motor (SRM) drives for use in hybrid and electric vehicles. Current control by a 3-level converter can reduce torque ripple by about 40% compared to the standard asymmetric 2-level half-bridge converter. The asymmetric neutral point clamped (NPC) converter is the preferred topology as a 3-level converter for SRM drives. This paper proposes an asymmetric T-type converter which has improved efficiency, reliability and cost compared to the standard asymmetric NPC converter for low voltage applications like electric vehicles. The switching table and operating modes for the proposed converter are presented. Vehicle models in MATLAB/Simulink are used to quantify the system-level converter performance compared to NPC for a standard city drive cycle.