Design of an Electric Drive Axle for Heavy Duty Commercial Vehicles in the Long-Haul Application Under Consideration of Energy Consumption

Abstract

In order to meet the challenge of electrification of heavy commercial vehicles with up to 41 t gross vehicle weight restriction, one possible promising approach is the development of a modular electric powertrain kit. In the following analysis, an integrated electric drive axle is designed for a 41 t tractor-trailer-unit in long-haul transport as part of a modular drive system with an integrated fuel cell. The lay out design begins with selected static driving profiles from which the requirements, such as the maximum drive torque and power, are derived for the drive axle. Subsequently, a concept with two permanent magnet synchronous motors and different gear stages is being analysed. In a parameter study, a simulation of the drivetrain in different driving cycles shows how a possible length variation of the motors and the change from a single- to a two-speed gearbox contribute to optimal energy efficiency and thus to lower energy consumption in the selected cycles. Furthermore, the existing conflict of objectives between motor and transmission package is addressed.