Efficiency improvement and evaluation of floating capacitor open-winding PM motor drive for EV application

An Open-Winding machine drive with a floating capacitor attached to one of the inverters has been demonstrated to be capable of extending the operating space of permanent magnet machines under a given power supply voltage limit. This paper applies this open-winding motor drive topology to electric vehicle application. The properties of this topology including sizing and efficiency are further investigated. A new voltage distribution scheme is proposed to optimize the inverter efficiency. Practical driving cycles, vehicle model and traction motor model are used in this study.