Estimating Crack Effects on Electrical Characteristics of PV Modules Based on Monitoring Data and I–V Curves

This study presents an approach to investigate microcrack effects on the output characteristics of photovoltaic (PV) modules based on a theoretical model that is derived from the equivalent single-diode model through monitoring data and current–voltage (I–V) curves. Meanwhile, an innovative parameter optimization algorithm based on particle swarm optimization is developed to extract the parameters. The parametric effects of microcracks on the electrical performance of PV modules are further explored under different meteorological conditions. It was found that the microcracks are formed early without creating inactive areas in solar cells, and the microcrack effects on the output performance of the PV modules are small. The temperature of the normally operating solar cells in a cracked PV module is lower than that of solar cells in a normal PV module. The number of equivalent mismatched solar cells caused by microcracks in the cracked PV module varies continuously with irradiance and temperature. Except for the apparently unaffectedI0, microcracks not only greatly reduce theIphandRshbut also have a more serious negative impact on theRsandnof the PV module at high irradiance. Meanwhile, then_normal,Rs_normal, andRsh_normalof the normal solar cells and theRsh_cracksof the cracked solar cells in the cracked PV module are exponentially related to the irradiance. Finally, the experimental validation is effectively implemented to prove the great effectiveness and suitability of the proposed method. The average voltage error of each reconstructedI–Vcurve based on the extracted parameters and the average errors inPm,Vm,Im, andVocof the cracked PV module for 532I–Vcurves are 1.15 V, 0.67%, 0.85%, 0.49%, and 0.089%, respectively.