Dynamic Modeling of Si-based Photovoltaic Modules using Impedance Spectroscopy Technique

In a scenario where the deployment of photovoltaic (PV) systems is increasing, the characterization and the monitoring of the state of health are pivotal. To this aim, Impedance Spectroscopy (IS) provides useful information about the dynamics of PV generators. In this work, an equivalent electric ac model for the characterization of PV modules is discussed. The model is applied to experimental spectra measured on a 52Wp c-Si based PV module in outdoor conditions. The fitting problem is solved by means of two different approaches, one based on the analytic solution of the model equations which employs few points of the experimental spectrum and the other based on an optimization algorithm, requiring the whole set of frequency points. The parameters’ values obtained from both approaches are commented, providing useful information on the behavior of the PV module under test.