Abstract
The content of this paper deals with the development and built-up of an 18 ton hybrid truck with a parallel hybrid drive train. Focus of the R&D Project was on the development a hybrid truck that enables pure electric driving up to 3 kilometres. Therefore an integrated motor generator with an additional clutch, a Li-Ion power battery, electrified high voltage auxiliaries, a cooling system and a hybrid control unit have been developed.
The beginning of the paper shows a detailed layout of the engineered hybrid truck. Chapter two shows the generated simulation model which was used for the dimensioning and detailed simulations of hybrid the drive train. To simulate thermal effects, a co-simulation environment between a longitudinal dynamics and thermal management software was applied. The coupling of longitudinal and thermal simulation enables a realistic calculation of the systems efficiency by temperature and load. Particular attention was given to electrical and thermal behaviour of the traction battery. The behaviour of this component has a high influence in the development and tuning of the vehicle’s components and operating strategy, as this is a very limited resource and lifetime depends very much on the load profile and cell temperature. Therefore a great amount of work was given to the development of the hybrid vehicles control software and the hybrid control unit. Finally simulated data of the hybrid commercial vehicle on standardized driving cycles were shown. These simulations show a meaningful influence on the temperature of the components, especially the battery and the hybrid vehicles operating strategy.
To gain high market shares for hybrid trucks the total cost of ownership will be the main driver. Therefore the development of well balanced and high efficient hybrid components such as traction battery, drive train, demand controlled auxiliaries and intelligent control strategies have to be the short term objectives.
KEYWORDS: Hybrid drives, commercial vehicles, heavy duty truck, power train, green technologies