Suitable Matlab-Simulink simulator for PV system based on a two-diode model under shading conditions

This paper proposes a photovoltaic system modeling and characterization software based on Matlab-Simulink in order to estimate the parameters and the characteristic and electrical behavior of a cell/module with respect to changes in environmental parameter regarding irradiance, temperature, and surface conditions (partial shading). The first objective is to find the parameters of the nonlinear I-V equation by adjusting the curve regarding three particular points: open circuit, maximum power, and short circuit. Given these three points, which are provided by all commercial module datasheets, the method finds the best I-V equation for the two-diode photovoltaic (PV) model, with the best series and parallel resistances estimates. The accurateness of the simulator is verified by applying the model to different manufacturer´s modules. Thanks to an interactive graphic interface, this software offers a great flexibility to PV professional and to researchers.