Model identification of a Proton-Exchange Membrane Fuel-Cell from an input-output experiment: The diffusive representation approach

This paper proposes a diffusive Proton-Exchange Membrane (PEM) Fuel-Cell (FC) model that reproduces the static and low-frequency dynamic characteristic of a PEMFC. Due to the nature of physical phenomena involved in a PEMFC, a fractional operator is a good candidate for describing its input-output behavior. In this paper, this operator is replaced by a well suited representation called “diffusive model” which simplifies its analysis and which leads to numerical realizations suitable for identification purposes. The diffusive model is approximated by a finite dimensional model that allows to formulate an optimization problem of least square error type to estimate the model distribution. The diffusive model is identified by means of experimental measurements of current (input) and voltage (output) in the FC. The obtained model is simple and can be used in systems that require real-time emulators or complex long-time simulations. The experimental results using the Ballard NEXA 1.2 kW fuel cell validate the advantages of the diffusive model.