Electric Powertrain Topology Analysis and Design for Heavy-Duty Trucks

Powertrain system design optimization is an unexplored territory for battery electric trucks, which only recently have been seen as a feasible solution for sustainable road transport. To investigate the potential of these vehicles, in this paper, a variety of new battery electric powertrain topologies for heavy-duty trucks is studied. Thereby, topological design considerations are analyzed related to having: (a) a central or distributed drive system (individually-driven wheels); (b) a single or a multi-speed gearbox; and finally, (c) a single or multiple electric machines. For reasons of comparison, each concurrent powertrain topology is optimized using a bilevel optimization framework, incorporating both powertrain components and control design. The results show that the combined choice of powertrain topology and number of gears in the gearbox can result in a 5.6% total-cost-of-ownership variation of the vehicle and can, significantly, influence the optimal sizing of the electric machine(s). The lowest total-cost-of-ownership is achieved by a distributed topology with two electric machines and two two-speed gearboxes. Furthermore, results show that the largest average reduction in total-cost-of-ownership is achieved by choosing a distributed drive over a central drive topology (−1.0%); followed by using a two-speed gearbox over a single speed (−0.6%); and lastly, by using two electric machines over using one for the central drive topologies (−0.3%).

Concept Studies on a Multifunctional Unit for Hydraulic Supply and High Lift Actuation in Aircraft

This paper investigates the potential of a new functionality of the hybrid Power Control Unit (PCU) in zonal electrohydraulic aircraft systems. The conventional PCU, as a hydraulic consumer, is the central drive for the leading and trailing edge flaps of an aircraft. Through extended functionality, it can also be operated as pump to provide hydraulic power in certain flight phases. The paper elaborates and presents different concepts for the integration of such a multifunctional PCU and evaluates the potential regarding mass savings and improvement of reliability. In subsequent simulation studies, the most promising concept is validated and analysed regarding the arising challenges.