Potentials of Dual-speed Transmissions in Electric Powertrains depending on Passenger Vehicle Segment

Abstract

This paper evaluates the potentials of dual-speed transmissions for battery-electric powertrains in different passenger vehicle segments. The evaluation takes into account the differing performance requirements as well as boundary conditions within these segments. Three design approaches, considering single and dual-speed transmission topologies as well as different power targets, are defined. For these powertrain concepts, the components electric machine, inverter and transmission are designed and simulated. Finally, the designed powertrains are holistically evaluated per segment on vehicle level and a comparison is conducted. We demonstrate that dual-speed transmissions can lower energy demand by up to 7.4 % compared to single-speed transmissions and that the effect increases with higher vehicle segment.