Simulation of Hybrid Electric Vehicles

In this work the fuel consumption of two vehicles is compared. For investigating the fuel consumption a whole vehicle simulation is developed with the SmartPowerTrains library and the SmartElectricDrives library. Both librarys are written in Modelica language. As a reference vehicle a conventional vehicle with manual transmission is modeled. A parallel hybrid electric vehicle with a starter/generator and two transition machines at the front and rear drive train wheels is compared with this reference vehicle. The operating strategy of the hybrid electric vehicle is explained. Furthermore, an analysis for finding the optimal sizes of the electric machines for the parallel hybrid electric vehicle using the developed simulation tools and the developed operating strategy is presented. The practical operation modes of the parallel hybrid electric vehicle are considered with regard to the implemented drive train configuration. A dynamic operating method is developed to determine the optimal power split between the internal combustion engine and the electric energy sources. The computer simulation results show the improved fuel consumption of the hybrid electric vehicle.