Predicting unparalleled degradation progression in PV module using simulation of shunt resistance experimental data

Datasets of various levels of solar cell shunt resistances were available in the literature, resulting in a linear correlation to forecast shunt resistance ( R sh ) degradation and failures in photovoltaic (PV) cells. However, some PV failures initiate mildly with one or few cells in a PV module and then distribute to other cells which leads to a major power reduction as well as critical safe operation. Simulating these experimental datasets gives the potential to catch these unparalleled degradations in PV modules at early stages, preventing them from turning critical. In response, SPICE simulation was used to study the effect of PV cells with low shunt resistance in a PV module. The simulation follows four steps, focusing on the electrical output of Current-Voltage ( I-V ) curve of the solar cells: (a) simulation of the experimental healthy I-V curve of a PV cell; (b) simulation of experimental eleven I-V curves at reduced levels of shunt resistance; (c) simulation of a PV module by using the simulation parameters obtained from the former steps; and (d) lastly, simulation of four different scenarios depending on the number of faulty cells in a PV module. The effect of these scenarios on the I-V curve parameters is compared. Results revealed it is feasible to detect unparalleled degradations, spotting the failed cells (reduced R sh ) in a PV module by implementing a linear model correlating open-circuit voltage (V OC ) with short-circuit-current (I SC ) (acting as a proxy of Irradiance) at different shunt resistance levels. This model can be simulated as a robust indicator of PV abnormalities and is appropriate for employment in online PV monitoring systems.