Fuel cell equivalent circuit models for passive mode testing and dynamic mode design

In this paper we present a review of the many dynamic equivalent circuit models that have been proposed for fuel cells and we compare their main characteristics and differences. We also identify the need for passive equivalent circuit models, particularly for use with back up power applications. Measured changes in the passive model parameters may also be useful indicators of the fuel cell´s capability under dynamic conditions. Based on experimental data from our work with a 25 W proton exchange membrane fuel cell, we have developed a passive model that considers the interaction of electrons and ions with the fuel cell´s electrodes and electrolyte. The response of this relatively simple model correlates well with the fuel cell´s measured response to three proposed external stimuli that could easily be automated