Accurate modeling and simulation of solar photovoltaic panels with simulink-MATLAB

Abstract

A unique procedure to model and simulate a 36-cell-50 W solar panel using analytical methods has been developed. The generalized expression of solar cell equivalent circuit was validated and implemented, making no influential assumptions, under Simulink/MATLAB R2020a environment. The approach is based on extracting all the needed parameters by exploiting the available parameters from the data sheets of commercial PV panels and by estimating the slopes at both short-circuit and open-circuit conditions of the current–voltage characteristic, usually provided by most solar panels manufacturers under standard test conditions (STC). The effects of solar irradiance and temperature were both considered in the modeling. A system of coupled nonlinear simultaneous equations for diode saturation current, diode ideality factor, and series and shunt resistances has been solved. To accurately model the PV module used in our simulation and analysis, the needed temperature- dependent parameters have been extracted for the first time. At STC irradiance of 1000 W/m2, the modeled I-V curve was found identical to the experimental one which is provided by the solar panel manufacturer. The maximum power output of the PV module increases from 8.75 W to 50 W when irradiance varies from 200 W/m2 to 1000 W/m2 at STC temperature. At temperatures higher than STC and for the same solar irradiance, the power output of the PV module came down about 14.5% only when the operating temperature reached a value of 65 °C. However, as temperature is below STC, the power output went up of about 7.4% beyond the maximum power of the rated PV panel. The calculated power temperature coefficient was about −0.39%/ oC which is quite close to the one provided by the solar panel manufacturer.