A Modified Current Source Inverter Fed Drive for Electric Vehicle Applications

This paper proposes a modified current source inverter (CSI) fed drive for electric vehicle (EV) applications. This topology utilizes an additional seventh switch, called CSI7, to significantly reduce commutation glitches of the traditional CSI. More importantly, with a proper pulsewidth modulation (PWM) scheme, the CSI7 topology yields reduced conduction losses, and thus improves the inverter efficiency. In this paper, the CSI7 topology is employed in an interior permanent magnet synchronous machine (IPMSM) drive. The drive includes a prestage dc-dc converter that acts as a controlled current source for the CSI7. Accordingly, a simple field-oriented control (FOC), utilizing a single current sensor, is proposed herein. Simulation results demonstrate a significant reduction in commutation glitches in output phase voltages and improved inverter efficiency. Both motoring and regenerating braking modes of the CSI7-fed drive are presented at various operating conditions. The proposed CSI7-fed IPMSM drive can be very attractive for EVs owing to its small battery requirement, thanks to its voltage boosting capability.