Hendrik Schröder

Energy Management for Fuel-Cell Hybrid Vehicles Based on Specific Fuel Consumption Due to Load Shifting

Energy management is integral to the design of fuel-cell (FC) hybrid vehicles (FCHVs), as well as topology and component sizing. Therefore, an optimal energy management strategy is crucial for a successful FCHV concept. The goal in this optimization process is to coordinate the energy sources and power components on a vehicle in such a way that the total consumption is minimized. We defined a new strategy that quantifies the shifts in the operating point (OP) of the FC system by using the specific fuel consumption due to load shifting and adapts the conditions for a possible shifting of the OP of the FC system to reduce the total fuel consumption. This paper shows the simulation results of the proposed strategy in comparison with existing strategies. The main focus is given on the improvement in fuel consumption, the effect of the new approach on utilization of the power sources concerning their aging mechanisms, and the effect of varying conditions by time. The results indicate that the goal of reduction in total fuel consumption is achieved.

Conceptual design of battery electric vehicle powertrains

Alternative vehicle powertrain systems are currently the most promising solutions to meet the energetic and ecological challenges in the individual mobility. To accomplish the keen competition, considering the decreasing lead time and costs for a vehicle design and the aim to develop the optimal powertrain design, methods that ensure a quick evaluation of various configurations of a powertrain system are required. Although utilising powertrain simulation models is a common approach in powertrain design, there is a need for quick generalised analytical models. In this paper, an analytical model is developed using the example of a battery electric vehicle (BEV) with the aim of a quick exploration of powertrain design solutions. Moreover, a comparison between the analytical method and a numerical simulative method with respect to their accuracies and complexities is shown. Finally, a Pareto frontier analysis of energy consumption, driving performance, range and cost for BEVs is accomplished.