Performance Evaluation of Two-Speed Electric Vehicles

This paper presents the findings of a theoretical analysis of a two-speed Dual-Clutch Transmission (DCT) for electric vehicle applications. Electric drives incorporating DCTs can offer improved driving economy, range, acceleration and climbing gradeability, with potentially smaller electric motors (EMs). Through simulation, this paper studies the influence of road grade on EV performance and how motor downsizing impacts on vehicle range and acceleration performance. Particular attention focused on how such vehicles perform using a variety of different drive cycles. Results show that as expected range is heavily influenced by driving cycle. However, for a reduction in motor peak power there is minimal variation in vehicle range. Vehicle performance is also demonstrated to be reasonable through significant reduction in motor size.