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The simulation and evaluation of land vehicle performance requires accurate representations of driving conditions. Currently, many driving cycles have been developed and used in the determination of vehicle fuel economy and emission performance. These driving cycles are typically defined as vehicle speed and power trajectories over time. However, most of the standard driving cycles are short in duration and distance and inadequate in representing a wide range of actual driving conditions. There are also many specialized driving cycles designed for specific types of vehicles, but these are often not applicable to more than a specific class of vehicles. Moreover, more detailed driving schedules are often kept as proprietary information within the vehicle manufacturers.

This paper presents a general formulation of the instantaneous power split between a fuel cell and an electrical accumulator in a charge-sustaining fuel cell hybrid vehicle. The approach proposed in this paper is based on the ECMS (Equivalent Consumption Minimization Strategy) control strategy previously developed for parallel hybrid vehicle applications suitable for real time application and allowing the overall minimization of hydrogen consumption while meeting the driver demand. This control strategy has been applied to a representative hybrid PEM (Proton Exchange Membrane) fuel cell mid-size vehicle. Using a Hybrid Fuel Cell vehicle simulator, the vehicle performance and energy requirements are estimated. The results provided by the ECMS control strategy approach are also compared to a more basic approach.