Study of the variation effect of solar panel temperature on the output characteristics of a solar power station under conditions of partial shadowing

The aim of the study consists in establishing the temperature variation effect appearing in individual banks of solar panels under conditions of partial shadowing on the current- and watt-voltage characteristics of the entire solar power plant, as well as in determining the mathematical model most adequate for reproducing this process. During the study, three different mathematical models (single-diode explicit, single-diode and two-diode) of solar panels were used as implemented in the MATLAB Simulink software package. In the modelling process, temperature variation for individual groups of solar panels is assumed to occur in the range from +35°C to+60°C under the conditions of shadowing from clouds of various density. In the present study, verification of the obtained data for implemented mathematical models based on Kyocera KC200GT solar panels with the same presented in the manufacturer's technical documentation was performed to prove the ability of these models to adequately reproduce the current- and watt-voltage characteristics. The most significant error in the obtained data (up to 18.31%) was a characteristic of a single-diode explicit mathematical model, while that of the single-diode model error was equal to 3.42%. The two-diode mathematical model was established to be the most adequate for reproducing the current-voltage characteristics of solar power plants in the conditions of partial shadowing. In order to obtain accurate output characteristics when modelling powerful solar power plants operated under conditions of partial shadowing, it is necessary to consider not only the change in the illumination rate for individual groups of solar panels, but also the corresponding temperature variation. In addition, for obtaining satisfactory results of mathematical modelling for a solar power plant under the studied conditions, an equivalent two-diode mathematical model of a solar panel is recommended.

modelling, electric power systems, solar power station, partial shadowing, two-diode mathematical model, single-diode model