Fault diagnosis in photovoltaic arrays

This paper proposes a simple automatic technique for fault diagnosis in photovoltaic (PV) arrays, based on the analysis of the an omalies observed in the I-V characteristic. Firstly, the I-V characteristic of the PV array is simulated using Matlab/Simscape tool for different faulty conditions; which is experimentally validated by generating different faults on a PV string installed at the Renewable Energy Laboratory of the University of Jijel (Algeria). Subsequently, we compare the I-V characteristic of the PV string under different faults scenarios, in order to identify the anomalies. Finally, six categories are generated: Normal operation, connection fault, connection fault with shadow effect, partial shadow fault, a group of fault which include shadow effect with faults on bypass diode (open circuit bypass diode, inversed bypass diode, shunted bypass diode), and a group of fault which include: bypass diode fault, cell fault, module fault, and shadow effect with shunted by pass diode fault. The results show that the technique can accurately detect and localize faults occurring in the photovoltaic string.