Electric Drive of the Future: Trade-Off Between Efficiency and Weight of an Innovative Electric Powertrain—Influenced by the Energy Costs Worldwide
摘要
The development of electric drives is currently aimed at a holistic improvement of power density, efficiency and sustainability at optimized costs. ZF has made notable progress with innovative approaches to the essential products power electronics, electric motor, and reduction gear as well as the intelligent overall synthesis. ZF’s electric drive system EVSys800 presented in 2023 is a prime example of this: 300 kW maximum power, 75 kg total weight and 70 Nm/kg power density. And further increase in power density is possible: Even more compact electric motors with higher numbers of pole pairs can eliminate further weight and reduce production costs. However, due to electromagnetic effects, efficiency is slightly reduced. This is precisely where the question of the right development focus arises: Does a significantly lighter and thus generally cheaper drive pay off despite slight efficiency disadvantages? And how do energy prices influence the direction of development? In order to derive future strategic corner points a lifetime analysis software model has been elaborated, which will be described in this paper. With this tool necessary future development steps can be predicted: This paper shows which values for efficiency, weight and power density can be expected in the performance class of 200 kW–300 kW in the future and which levers are available for further improvement. In addition, it is compared to what extent the expected battery and energy prices influence the adjustment of these levers. This might result in different regional solutions.