Avaliação da injeção de harmônicos em um sistema fotovoltaico conectado à rede de baixa tensão com módulos danificados por impactos mecânicos

Abstract

The growth of distributed generation through grid-connected photovoltaic systems has increased the need for studies related to the reliability and quality of the electrical energy supplied. Some situations negatively influence the performance of photovoltaic systems, such as mechanical failures in modules, altering the electrical characteristics of the array and resulting in a possible intensification of harmonic component injection into the electrical grid. Therefore, this study aims to evaluate the impacts caused by mechanical failures in photovoltaic modules on harmonic injection in a grid-connected photovoltaic system operating at low voltage. To achieve this objective, a literature review on the relevant topics was conducted along with an experimental analysis carried out in a photovoltaic system installed at the Laboratory of Technology and Renewable Energy (LATER) of the Federal Institute of Pernambuco (IFPE) – Garanhuns Campus. In the experimental stage, three scenarios were defined for evaluation: the first with all modules intact, the second with one damaged module, and the third with two damaged modules. The data were obtained using a power quality analyzer connected to the system and configured according to the requirements established by current technical standards. The measurements were performed for at least seven days, totaling 1008 valid readings. The results demonstrated that the introduction of damaged modules did not result in significant changes in voltage and current harmonic distortion levels. The indicators related to voltage harmonics remained within the limits established by technical standards for low-voltage systems, while current harmonic distortion values showed variations mainly influenced by the operational and environmental conditions of the system, especially solar irradiance and the inverter operating regime. Therefore, under the analyzed conditions, the mechanical failures in the photovoltaic modules did not compromise the power quality supplied to the grid.