Technology Challenges and Trends of Electric Motor and Drive in Electric Vehicle

Abstract

Electric traction drive systems must demonstrate advanced capabilities, such as improved fuel efficiency measured in miles per gallon of gasoline-equivalent (MPGe), extended range, and rapid charging options to achieve wider acceptance. This increased electrification and evolving mobility landscape have generated a demand for electric traction drive systems with higher power output and greater efficiency, resulting in better fuel economy per battery charge. To accelerate the widespread adoption of electrified transportation, the US Department of Energy (DOE) has collaborated with the automotive industry to establish technical targets for light-duty electric vehicles to be achieved by 2025. Deployment of publicly available EV charging points increased by close to 40% in 2021, although in 2020 the growth rate was higher at 45%. Nevertheless, 500 000 public charging points were installed in 2021, which is more than the total stock of chargers available in 2017. The rate of fast charger installations increased slightly in 2021 (up 48%) compared with 2020 (up 43%), while growth in slow charger installations slackened (33% in 2021, compared with 46% in 2020). This article investigates the current trends in electric drive technology for both hybrid electric and fully electric passenger vehicles. It evaluates commercially available solutions concerning materials, designs for electric machines and inverters, maximum speed, power density, and component cooling, as well as performance metrics. Furthermore, the article highlights upcoming materials and technologies for power electronics and electric motors, as well as the associated challenges and opportunities for achieving even more ambitious designs to meet the demands of the next generation of electric vehicles.