System identification black box approach for modeling performance of PEM fuel cell

A polymer electrolyte membrane (PEM) fuel cell is very useful for distributed generation and for portable users like electric vehicles because it is very efficient, emission free and operated at low temperature. However, it is not so easy to find direct experimental estimates of the actual performance of PEM fuel cell through various phenomena and operating conditions like chemical reactions, fuel pressure, working temperature and fuel humidity. Mathematical modeling, therefore, plays an important role in understanding operational performance of PEM fuel cell. The actual operating performance of PEM fuel cell depends on a number of parameters, therefore developing an accurate model that includes its dynamic behavior is most important. In this paper, first time, the system identification black box approach is used to develop a number of simple but more realistic mathematical model structures for a PEM fuel cell. The performance of each model structure is compared with the data from a 25 cm(2) active area practical PEM fuel cell for result validation. The presented models can be used to predict polarization behavior of the PEM fuel cell under different loading conditions.