Abstract
Keywords: Hybrid powertrain, Hybrid electric truck
Due to the strict environmental rules the manufacturers intends to reduce their vehicle's emission. Several methods exist to decrease the emission of the internal combustion engines like alternative fuels or using hybrid powertrain. In case of hybrid technologies the wheels are acted not only by the internal combustion engine but an electric motor/generator is inserted somewhere in the driveline as well. Depending on the performance of the electric motor different type of hybrid systems exists, like micro-, mild- and full hybrids. The hybrids can be sorted as parallel or serial construction as well depending on the drive paths. In this paper we develop a model of a conventional and a hybrid light duty commercial vehicle to analyse and compare them under distribution operation situation. The main aspect of this paper is to emphasize the benefit of the hybrid vehicles not just in case of a single passenger car, but also at light duty trucks in fact using a fleet of them.
The model contains a detailed internal combustion engine, the whole powertrain with electric motor and the batteries in case of hybrid vehicle. The internal combustion engine model has cylinders, cranktrain, intake and exhaust pipeline system and fuel injection system. The flow in the pipelines is modelled in one dimension in longitudinal direction. A predictive combustion model is applied which computes the flow in the combustion chamber and a DI jet model is used to calculate the heat release rate. It allows analysing the emission of the engine, too. Two different engine models are created for the two vehicles, which have different displacement volumes to ensure correct comparison the hybrid and the conventional vehicle, to have the same power apart from the hybrid driveline. So the total power measurable on the wheels are approximately the same, they have the same transmission, the same differential gear, and the vehicle body as well.
The analysis demonstrates the advantages in fuel consumption and emission values for different scenarios like urban goods distribution. With the results it is possible to compare the emission of both types of vehicles, furthermore using the consumption data we make an economic efficiency, or even a cost benefit analysis as well.