New PWM Switching Strategy for a Dual Inverter Fed Open Winding Motor Drive System

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 paper, a new PWM switching strategy of the inverters is presented when the motor is operating in the medium and high speed region. The PWM switching strategy consists of operating one of the inverters in the low switching frequency 1 pulse (square wave) mode and the other inverter in the high switching frequency specialized continuous pulse width modulation (SCPWM). The new PWM strategy has been verified from suitable simulation and experimental results in the medium speed range. 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 improve the drive system efficiency.