Avaliação da dinâmica de nuvens e do impacto em redes de distribuição com grande participação de geração fotovoltaica

Abstract

The search for a more diverse energy matrix, to decrease the fossil fuel consumption com-bined with the enhance concern of environmental impacts results in an increasing interest on the installation of distributed generators. Nevertheless, its technical impacts must be studied carefully to benefit electric energy distribution systems. Considering photovoltaic generators, the presence of clouds influences directly in the solar irradiance on Earth’s surface, what var-ies, in a significant way, the generation of energy throughout time. The continuous clouds movement above electrical grids that contain this kind of generation produces difficulty in the forecast variations of the generated power flow and voltage fluctuations on electrical grid im-pacting the consumer’s energy quality. Thus, this master dissertation proposes to rank real solar irradiance data according to satellite image processing, which counts on information referring to the different sort of clouds. The purpose is to investigate how the dynamic of clouds affects the energy production from photovoltaic generator and, consequently, the im-pact on the electrical grids that counts with it. At first, different types of clouds are ranked through image processing techniques, so that images were obtained in CPTEC. Weather Fore-casting and Climate Studies Center website using satellite GOES-13 data with 30 minutes periods. In comparison to image processing results, it is used measured data from a photovol-taic system installed on the roof of Block E from Santa Maria’s Polytechnic School to rate the shading influence, thus, the classification of measured data on: sunny, partially clouded and fully clouded days. Therefore, for the evaluation of impact of a photovoltaic systems on dif-ferent generation situations over an electric distribution grid, it was used the IEEE 34-bus feeder, through known analysis such as QuasiStatic Time-Series Analysis performed by the software Open Distribution System Simulator (OpenDSS). Different load profiles are also considered, such as constant and variating loads on weekdays and weekends. The results in each tested case are presented and is performed an analysis of information from the energetic point of view, observing the real and local generation capacity, and the quality of the energy provided by the system, in which is referred the voltage levels and operation of voltage regu-lators equipment.