Multilevel converter topologies for high-power high-speed switched reluctance motor: Performance comparison

In this paper, two topologies for SRM drive is proposed, namely five level asymmetric neutral point clamped and asymmetric modular multilevel converter for high speed and high power SRM drive. For high speed operation, back EMF of the motor increases to high levels. Therefore, input voltage should be more than back EMF in order to force current into the winding. Multilevel converter can apply variable dc input voltage over a wide high speed range. Additionally, it can shape the phase current easily with multiple dc voltage levels to reduce high frequency torque ripple, thereby minimizing vibration. Operation of the proposed converters is verified using Matlab Simulink and performance comparison in terms of torque ripple and efficiency is evaluated. Also, performance of the drive is studied for different dc link voltage levels and the corresponding effect on efficiency is evaluated.