Alternative PWM Switching Strategy Implementation for a Dual Inverter Fed Open Winding Motor Drive System for an Electric Vehicle Application

The dual inverter fed open winding interior permanent magnet synchronous motor (DIF-OW-IPMSM) is a promising traction drive system configuration for a high power and high efficiency electric vehicle. In this article, for an electric vehicle application, an alternative PWM switching strategy of the DIF-OW-IPMSM is presented when the motor is operating in the medium and high speed regions. The alternative PWM switching strategy consists of operating one of the inverters in the low switching frequency synchronous 1 pulse (1P) mode and the other inverter in the high switching frequency asynchronous specialized continuous pulse width modulation (SCPWM) or discontinuous pulse width modulation (SDPWM). Preliminarily, the alternative PWM switching strategy has been verified from suitable simulation and experimental results with a dual Si-IGBT based inverter. Finally, a dual inverter configuration with a hybrid combination of Si-IGBT inverter and SiC-MOSFET inverter is recommended for a premium class electric vehicle to further improve the drive system efficiency. Suitable experimental results and relevant logical arguments are given for the dual inverter based on Si-IGBT and SiC-MOSFET to support the concept.