Research overview : design specifications for hybrid vehicles

In this paper a method is proposed for determination of the design specifications regarding the energy exchange systems for different chargesustaining hybrid vehicles of different vehicle classes. Hybrid drivetrains for vehicles combine multiple power sources in order to increase the driving functions. The function can enhance the fuel consumption, emissions, comfort, driving performance and safety. In this paper the focus is on fuel consumption reduction. The optimal energy management strategy is determined by using dynamic programming. Initially, the efficiencies of the energy exchange between the engine, vehicle road load and additional energy exchange system are assumed to be constant and independent of engine torque and speed. Therefore, the simulation results will be independent of the component technology and topology. The outcome of the simulations will be the required constant system component efficiencies, sizes and power specifications in order to achieve the required fuel consumption reduction, maintain state-of-charge and accomplish any power demand over a defined drive cycle. These design specifications will be used to chose system component technology. Finally, the chosen system component technologies will be used to determine optimal topologies and optimal energy management system control.