Fractional order model for diagnosis of flooding and drying of the proton exchange membrane fuel cell

The diagnosis and control of PEMFCs hydration states depend on the reliable models and methods of monitoring of system operating. Impedance spectroscopy was generally used to describe fuel cell systems and derived impedance models. This study investigated the characterization and diagnosis of fuel cells by using fractional order impedance model as an explicit transfer function and factor design methodology (DOE) to determine the model parameters. The physical parameters appeared very sensitive to humidity and then used for monitoring and diagnosing of fuel cells. The proposed model is suitable to represent Randles impedance model equivalent electrical circuit enhanced by CPE, with the ability to generate the Nyquist impedance spectra easily for all conditions of relative humidity and operating time. The comparison between the literature experimental impedance spectra in both cases (drying and flooding), and the spectra simulated by the explicit fractional order impedance model demonstrated that the proposed model was robust and reliable and can, therefore, be integrated into the PEMFCs water management system. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.