Experimental Characterization and Modeling of PEM Fuel Cells under Dynamic Load Variations

The adoption of fuel cells (FCs) for industrial applications, transportations and home power generation is widely increased during recent years. Because FCs are still in the development stage, to evaluate and validate fuel cell technologies suitable test systems are needed. In a fuel cell both chemical and electric sections can be founded, so to control its behaviour the measurement of different parameters, as current, voltage, flow rate of the reactants and cell temperature is required. The performance evaluation of a fuel cell requires both static and dynamic characterizations, especially for the automotive applications, in which there is a dynamic variation of electric load. To better design this kind of applications, a FC mathematical model is required, to evaluate the performance at different working conditions. The synthesis of a dynamic model describing the FC behavior should be performed starting form the real system configuration, including pipes, flow and pressure regulators and valves. To this aim an automatic measurement system for the characterization of PEM (Polymer Electrolyte Membrane) fuel cells has been developed, and in this paper a dynamic model of a fuel cells stack is proposed, which has been validated through experimental measures. Key-Words: Fuel cells, Test system, Characterization, Data acquisition system, Dynamic testing, Supercapacitor