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This paper deals with the analysis of a hydrogen-air fuel cell system based on a Proton Exchange Membrane (PEM) fuel cell stack. The goal of the analysis is to understand the impact of stack water and thermal management on the system both during steady state and dynamic operations. The stack level study is done in terms of liquid and water vapor flows and distribution via a detailed stack water management model. An analysis of the stack and the system level implications of varying the anode saturation temperature is performed. It is shown that increasing the anode saturation temperature potentially enhances stack performance but need not improve system performance.

This paper examines the impacts of fuel cell system parameters and control strategies on the dynamic response of an indirect-methanol fuel cell vehicle (FCV). An indirect-methanol fuel cell system model is introduced and explained, and then the effect of parameter variations on the vehicle acceleration from 0-60 mph (ca. 0-100 kph) is analyzed. Varied parameters are the fuel processor response time, the utilization rate and the fuel cell system size (qualitatively). In addition two different fuel cell system control strategies are introduced and are compared with respect to their impact on vehicle acceleration. If poor fuel processor dynamics are the limiting factor, the vehicle acceleration can be improved adopting an alternative control strategy -- without major changes in hardware but accepting a lower fuel economy.