Improving the accuracy of the single diode PV models

Abstract

Single diode PV circuit models have been used widely in the literature for their simplicity. Although they are sufficiently accurate at standard test conditions (STC), they exhibit deteriorated accuracy at low levels of irradiances. This paper enhances the accuracy of single diode models at lower irradiances without affecting their simplicity. It modifies the saturation current equation to improve the accuracy under irradiance variations. The accuracy improvement is demonstrated by comparing the performance of the models, with and without the proposed modification, to the measurements provided by manufacturing datasheets of the three PV technologies available commercially; mono-crystalline, poly-crystalline, and thin-film.