Real Time Fault Detection in Photovoltaic Systems

In this paper, a method for real time monitoring and fault diagnosis in photovoltaic systems is proposed. This approach is based on a comparison between the performances of a faulty photovoltaic module, with its accurate model by quantifying the specific differential residue that will be associated with it. The electrical signature of each default will be fixed by considering the deformations induced on the I-V curves. Some faults, such as: interconnection resistance faults and different shading patterns are considered. The proposed technique can be generalized and extended to more types of faults. The fault diagnosis will be determined by fixing a normal and a fault threshold for each fault. These thresholds are calculated based on the Euclidean norm between ideal and normal measurement or between ideal and fault mode measurement. Each threshold is set in a range bounded by the minimum and maximum values of the differential residue obtained for the considered fault. The proposed approach provides identification of faults by calculating their specific threshold ranges. This method allows the instantaneous monitoring of the electrical power delivered by the photovoltaic system.