Efficiency assessment of electric propulsion systems for electric vehicles

An efficiency analysis of different configurations of Electric Propulsion Systems (EPSs) is presented in this paper. Particularly, three different Permanent Magnet Synchronous Machines (PMSMs) have been considered as the electric motor, which are characterized by different speed operating ranges and constant-power speed regions. In addition, four transmission systems are introduced and briefly described, i.e. Single-Gear, Multi-Gear, Continuously Variable and Magnetic Gear Transmission. Among these, the most suitable one is chosen for each PMSM in accordance with its inherent features. Subsequently, four EPSs have been designed based on specific vehicle traction and power requirements. The proposed EPS configurations are tested over three driving cycles in order to assess their efficiency over different driving conditions.