Modeling and Experimental Determination of the Circuit Parameters of Thin Film PV Modules/Arrays

Abstract

Nowadays, photovoltaic (PV) systems are more and more widely diffuse in the energy networks, with growing size of the installations. For relatively large sizes, the effect of parasitic parameters (capacitive and inductive) becomes more relevant. Thus, it becomes interesting to characterize the effects of these parameters on the PV system operation and to include these effects in the PV system models. In the classical model of PV cells or modules, based on single exponential or double exponential representations, the parasitic parameters are ignored. In order to include the effects of these parameters, it is possible to elaborate the experimental results obtained by the transient charge of an external capacitor connected to the PV generator terminals. Proper selection of the external capacitor can lead to highlight the effects of these oscillations, making it possible to interpret the behaviour of a PV module or array through suitable analytical models. Refined assessment of the parameters is then possible by synthesizing the experimental results of multiple executions of the transient charge of the capacitor through minimum error-based computational procedures. In this paper, a model containing the classical and parasitic parameters is constructed on the basis of the results obtained by fast sampling of the voltage and current waveforms gathered during the transient charge of an external capacitor. The assessment is carried out with particular reference to thin film technol