Análise e desenvolvimento de controles para geração híbrida fotovoltaico-diesel

Abstract

The systems of generation, transmission and distribution of energy are always in constant expansion. However, according to the Energy Research Company (EPE), in 2022 there were are around 250 isolated locations in Brazil, representing 1.5% of the population that live in remote regions of the country and that are not connected to the SIN. The supply of these regions is carried out by microgrids, formed mainly by Diesel Motor Generator Sets (GMG), which are easy to design, build and operate. However, this equipment has a high fuel consumption, considerable maintenance costs and the use of fossil fuel harms the environment. To mitigate these problems would be the adoption of isolated photovoltaic (PV) systems, which are disconnected from the electrical grid and when there is no solar radiation, energy is supplied by batteries. Due to the low useful life of the batteries and due to their high acquisition cost in Brazil, the implementation of these systems ends up making many projects economically unfeasible. Another solution would be the adoption of hybrid microgrids where a renewable source such as PV could contribute with its energy, thus reducing GMG generation. However, its association with a PV generation, directly and without any control, can cause damage to the GMG and also, in case of actuation of the protection system, leave the microgrid without electricity. These problems are associated mainly due to the intermittency of PV generation, caused by oscillations in solar radiation. Thus, this work proposes the development of methodologies, which aim to guarantee a high PV penetration in a hybrid PV-GMG microgrid, thus enabling a greater reduction in the fuel consumption of the GMG. It is also proposed a control system that aims to ensure that the GMG operates without exceeding its minimum generation limit. The test system indicated for the validation of methodologies took into account the reconfiguration of a part of the Federal University of Santa Maria (UFSM). Thus, allowing distribution network, allowing the formation of a hybrid microgrid with PV generators, GMG and existing loads. The microgrid was modeled and simulated using Matlab/Simulink® software, where it was possible to verify that the proposed methodologie managed to stabilize the microgrid, even with high PV penetration rates. Through an economic analysis, carried out with the HOMER® software, a reduction of 18% in fuel consumption was also verified.