Enabling Technologies for Compact Integrated Electric Drives for Automotive Traction Applications

The electric traction drive is the main consumer of the stored energy in an electric vehicle. Therefore, the drive system must perform with high efficiency to maximize the vehicle range for given battery capacity. Since the introduction of hybrid electric vehicles, various innovative traction drive technologies have been implemented in commercially available electric vehicles to increase efficiency and power density. It is expected that the power density and performance of the traction drive unit must improve significantly for future electric vehicles to increase the user space in the vehicle, extend the range and increase market adoption. US Department of Energy (DOE) has recently announced technical targets for light duty electric vehicles. DOE targets to reach a power density target of 33 kW/L for a 100 kW traction drive system by 2025. It is an increment by a factor of 5.5 in comparison to the state-of-the-art. This paper investigates the current trends in commercially available electric drives for light-duty automotive applications, identifies the challenges, and discusses innovative technologies to overcome the power density barrier.