A Partial Shading Detection Algorithm for Photovoltaic Generation Systems

Photovoltaic (PV) systems have been gaining great attention during the last decade. One of the main faults in PV arrays is partial shading, affecting its electrical parameters. Failure to detect this fault may result in optimal generated power reduction and hot spotting leading to damage to cell encapsulant and second breakdown. This paper develops a partial shading detection algorithm that only requires the available measurements of array voltage and current. By quantifying the wave-shape of the super-imposed component of PV array power by the skewness function, it can discriminate a partial shading condition from the short-circuit and high-resistance faults. The developed scheme is implemented in a central intelligent electronic device and does not require a communication link and training data set. The merits of the proposed partial shading detection algorithm are demonstrated through several fault scenarios using a 5×5 grid-connected PV generation system.