Comparison of Equivalent Circuit's Parameters Obtained for Half Cells of PV Mini-Modules Tested under Sunlight and Partial Shading

This paper aims is included in a line of research aiming to develop an automatic acquisition system for the fault detection in PV plants. The performance of photovoltaic (PV) generators can be modeled using electrical equivalent circuits with parameters ranging from three to seven. This study compares the equivalent circuits to extract the parameters for half-cells of PV modules tested under natural sunlight and partial shading. The tests, conducted at Politecnico di Torino (Italy), reveal that the four-parameter model provides an optimal balance of accuracy and computational efficiency under sunlight, whereas the five-parameter model demonstrates higher accuracy under partial shading. These insights are essential for implementing effective fault detection systems in PV plants to distinguish between faults and suboptimal operating conditions such as partial shading.