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Vehicle manufacturers claim that fuel cell vehicles are significantly more fuel-efficient and emit fewer emissions than conventional internal combustion engine vehicles /1/. A computer model can help to explore and understand the underlying reasons for this potential improvement. In previous published work, the UC Davis Vehicle Model for the case of a load-following Indirect Methanol Fuel Cell Vehicle (IMFCV) has been introduced and discussed in detail /2/. Because of possible technical barriers with load following vehicles, as well as near term cost issues, hybrid fuel cell vehicle concepts are widely discussed as another fuel cell vehicle option. For load following vehicles, the questions of fast start up and fuel processor dynamics in extreme transient situations, (e.g., during phases of hard acceleration) are not totally resolved at this time. For both of these performance issues, a hybrid design could offer at least an interim solution.

This work focuses on the algorithms to simulate and analyze the characteristics of an indirect methanol fuel cell vehicle. The individual components of the electric drive train including transmission, the vehicle properties, such as drag, frontal area, wheel inertia etc., and the fuel cell system are modeled in a dynamic manner. Further the interaction between the individual components and a simple driver model is described. The algorithms are coded using the simulation tool Matlab/Simulink. The simulation tool is strictly setup in a modular form allowing modifications of individual component characteristics or control algorithms without the need to change the remainder of the model. For the benefit of a more in depth discussion of the applied algorithms and the setup of the model this paper focuses solely on the case of an Indirect Methanol Fuel Cell Vehicle (IMFCV) with steam reformer and without any additional energy storage.