Experimental Analysis of Equivalent Circuit's Parameters for Half-Cell Photovoltaic Modules Under Natural Sunlight

In literature, the equivalent circuits of solar cells permit to approximate the electrical performance of PhotoVoltaic (PV) modules. This work is inserted in a research field aiming to develop a model for the automatic diagnosis of PV plants by their inverters based on the equivalent circuit's parameters. However, identical PV modules, generally, have slightly different electrical performance, and, hence, different equivalent circuit's parameters. Since the diagnostic model will need to take into account such differences for the PV modules of a plant, this work proposes a statistical evaluation of the equivalent circuit's parameters extracted for eight identical half-cell PV modules, which were tested under natural sunlight. Their I-V curves were corrected to Standard Test Conditions with an analytical procedure provided by an international standard, and the equivalent circuit's parameters were numerically determined for all the modules. Finally, the most important statistical quantities as mean, median and standard deviation were determined for each parameter.