Estimation of Parameters of Photovoltaic Modules Based on Ideality Factor Variation

The paper presents a method for calculating the parameters of a one-diode equivalent circuit of solar panels/cells. This approach is based on iterative search of the value of the ideality factor and analytical determination of other parameters, the purpose of which is to minimize the approximation error of the I-V curve. To minimize the approximation error near the maximum power point, a normalized power curve is used, which is calculated based on the digitized I-V curve of the solar panel. Examples of the use of this method for polycrystalline KC200GT and thin film ST40 panels were given. A comparative analysis was also conducted with similar articles on this topic, which showed that the proposed algorithm provides an average of 7.56 times less error for polycrystalline panels and 2.95 times less error for thin-film panels compared to the considered works.