Optimized Design of Multi-Speed Transmissions for Battery Electric Vehicles

This paper considers the optimization of multispeed transmission configuration and gearshift schedule for battery electric vehicles. Although only a single reduction gear is commonly utilized in commercial battery electric vehicles, further improvements in energy savings can be achieved by employing a multi-speed transmission as has been already shown in existing literature. In this paper, we propose an approach to co-optimization of transmission design (number of gears and gear ratios) and of gear shift schedule. The simulation results quantify the battery energy savings which are achieved by the proposed approach and the ability to obtain shift schedules that promote regenerative braking.