Análise da qualidade da energia elétrica em um sistema fotovoltaico conectado a rede

Abstract

The deep changes that electric power distribution systems have been experiencing due to the growth in the use of Distributed Generation have resulted in a change in the traditional way of controlling and operating the electrical system. The large-scale connection of DG units poses a number of technical, economic, and regulatory challenges for power utilities that are required to maintain reliability, continuity of supply, and the level of Electrical Power Quality in the system, mainly due to the bidirectionality of the power flow in the network. Recently, the project “Energy Efficiency and Minigeneration at the Federal Institute of Goiás (IFG) was created, where photovoltaic solar micro and minigigeneration systems will be installed with total capacity of 1MWp distributed in 9 IFG campuses, namely: Anápolis, Aparecida de Goiânia, Formosa, Inhumas, Itumbiara, Jataí, Luziânia, Valparaiso and Uruaçu. Given the above, the purpose of this work is to analyze the impacts of distributed generation, specifically photovoltaic, on the low voltage secondary distribution network, under parameters of Harmonic Disturbances and Voltage Disturbances, through data collected from a photovoltaic distributed generation of 70 kWp present at IFG campus Itumbiara. The technical data of the system were obtained from the technical documentation regarding campus implementation, the load curve obtained from on-site measurement using the power quality analyzer, and the comum point linkage data granted by ENEL. In this work the correlation between system operation and impacts observed in the parameters to be approached is made, aiming to technically analyze the QEE of the system in question. It was observed that the operation of the IFG Grid Connected Photovoltaic System impacted the voltage profile, which increased during periods of high generation, characterized by the injection of the active power surplus into the grid. It can also be verified that this system in nominal operation did not cause extrapolation in the limits of harmonic voltage distortion, as well as in the voltage unbalance. In periods of low production, there was an increase in the harmonic distortion of the electric current injected by the photovoltaic inverter.