Dedicated Hybrid Transmission for Commercial Vehicle Applications: Mechanical layout, system analysis and simulation of a dedicated hybrid transmission for commercial vehicles

摘要

This Paper presents a new dedicated hybrid transmission for various commercial vehicle applications, which AVL is developing as part of a customer project. This new hybrid transmission uses a combustion engine and two highly integrated, high-speed e-motors as its drive sources. With the help of a sophisticated but comparatively simple transmission concept, high efficiencies, low product costs and a transmission design which is adaptable to different commercial vehicle applications are achieved. The high efficiency of the drive train and the perfectly coordinated interaction of the three drive systems ensure high fuel savings without compromising drivability and driving comfort. This is achieved, in particular with dynamic load profiles as they are usual for city bus applications, via power-split and pure electric vehicle operation mode. In addition, an overdrive operating mode enables efficient driving at constant and high vehicle velocities for highway applications. Thereby, an optimum operating range for the combustion engine is achieved via a mechanical power flow and parallel hybrid function. The operating mode is selected on the basis of a well-developed hybrid strategy. Based on the results of a vehicle simulation, the new dedicated hybrid transmission can achieve significant fuel savings compared to modern, conventional commercial vehicle powertrains.