MODELING OF PV MODULE CURRENT-VOLTAGE CHARACTERISTIC WITH VARIATIVE IDEALITY FACTOR AND REVERSE SATURATION CURRENT.

In the work the current-voltage characteristic (CVC) of photovoltaic modules (PVM) were measured by fast scanning them using an automated system developed by us on the Raspberry Pi microcomputer platform. A theoretical model and an algorithm for processing experimental data have been developed for the analysis of PVM parameters changes with voltage. The voltage dependences of the ideality factor of the pn junction, the reverse saturation current and their influence on the CVC have been clarified. Numerical determination of these parameters allows characterizing electrical losses and recombination processes in solar cells under various external conditions. It is shown that ideality factor can be significantly exceeds 2 in the voltage range less than the maximum power point. This is characteristic for PVM manufactured using modern technologies. The changes of the reverse saturation current and its growth in a certain voltage range due to significant recombination current were analyzed. [ABSTRACT FROM AUTHOR]