Estudo e análise de desempenho de geradores fotovoltaicos distribuídos com vistas à avaliação de procedimentos para identificação de sinais de degradação e suas respectivas causas

Abstract

This work presents the study and application of techniques for the evaluation of photovoltaic modules under the influence of the main forms of degradation and their respective impacts on the generation of electric energy. A total of 48 photovoltaic modules were analyzed, from 5 different models, totaling a peak power of 10.16 kWp derived from the photovoltaic system installed at the Research Laboratory of Power Electronics at the Federal University of Uberlândia (NUPEP-FEELT-UFU). To evaluate the degradation visual inspections were performed. Also, for the analysis of the thermal distribution on the surface of the modules, thermography images were obtained with the purpose of identifying hot spots and associating them with the signs of degradation found in the inspection. In addition, to quantify the impact of failures in power generation, I-V curves were measured locally in 2016, 2017 and 2018, individually and by strings. Additionally to the main analysis of module degradation impacts, tests were carried out to evaluate the impacts of dirt on the modules and the main results were presented. For the tests of I-V curves carried out in 2016 and 2017 a significant difference between values of maximum power measured in loco and the minimum power reference calculated from datasheet information. In order to evaluate the veracity of the results, all the parameters used to obtain the I-V curves were evaluated and it was verified the need to correct the operating temperatures of the cells and new values of maximum power were obtained following the procedures of IEC standard EN 60891.