967 resultados para Painel fotovoltaico
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Solar energy can be considered the largest source of energy available on earth and has attracted in recent decades, attention and interest for its rational use. The use of energy sources in a sustainable manner is essential to the survival of future generations, due to the scarcity of natural resources and their exploitation in a disorderly way. Studies related to the applications of renewable sources becomes then relevant, given its great importance as regards the conscious use of resources provided by nature, with the least possible impact on it. The present study presents an evaluation of generation potential and feasibility of implementing a solar photovoltaic connected to the grid and connected to the roofs of some buildings of the Faculty of Engineering of Guaratinguetá - FEG, to supply the demand of electric energy consumption on campus and attempting to inject a possible surplus power generation in local power grid, increasing network capacity and reducing peak loads
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The research aimed to produce sheets of particles with waste processing of Eucalyptus sp bonded with urea-formaldehyde and evaluate the effect of pressure variation in the quality of the boards produced. To do so, the Boards made were divided into two treatments depending on the pressing pressure of 30 to 40 kgf / cm². Once pressings, climatized, the particleboards have been sectioned in test samples, and underwent physical-mechanical tests for determining density, swelling and water absorption, modulus of rupture and elasticity in static bending and internal linking. The particleboards pressed at 40 kgf / cm ² showed the best results
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Solar energy can be considered the largest source of energy available on earth and has attracted in recent decades, attention and interest for its rational use. The use of energy sources in a sustainable way is essential to the survival of future generations, due to the scarcity of natural resources and their exploitation in a disorderly way. This academic work aims to bring a possible alternative to reduce the consumption of eletrical energy, at the University of Engineering – Campus of Guaratinguetá, through the use of a photovoltaic system interconnected to the LED bulbs. For this, the necessary data for the design of the photovoltaic system componentes and their acquisition costs were obtained and three differents configurations were developed to choose the one that bests fits the studied case, considering the return time of the initial investment (payback)
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This work presents a study about distributed generation using photovoltaic systems in the context of smart grids. The characteristics of a Smart Grid and the several aspects this concept involves - distributed generation among them - are discussed. There are also examples of equipment, like smart meters, and of national and international projects. The specificities of distributed generation and the rules and standards necessary in this sort of installation are talked through with focus in the solar energy generation method. Regarding photovoltaic systems, the working principles of the panels are presented, along with its main electrical characteristics and the technologies available. Finally there is a study concerning the sizing of a distributed generation system that involves photovoltaic panels in a residential plant. An analysis of the costs and return of investment period is made about the specific case in consideration.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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This paper shows the modeling and control of a single-phase full-bridge inverter with high-frequency transformer that may be used as part of a two-stage converter with transformerless DC-DC side or as a single-stage converter (simple DC-AC converter) for grid-connected PV applications. The inverter is modeled in order to obtain a small-signal transfer function used to design the P+Resonant current controller. A highfrequency step-up transformer results in reduced voltage switches and better efficiency compared with converters in which the transformer is used on the DC-DC side. Simulations and experimental results with a 200 W prototype are shown. 1
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Pós-graduação em Engenharia Mecânica - FEG
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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The Earth receives annually 1,5.1018 kWh of solar energy, which corresponds to 1000 times the world energy consumption in this period. This fact comes out that, besides being responsible for the maintenance of life on Earth, the solar radiation is in an inexhaustible energy source, with an enormous potential for use by systems capture and conversion into another form of energy. In many applications of low power systems that convert light directly into electricity, called photovoltaic advantageously replace other means of production processes, where its distribution is very significant. The determination of the power generated by such a system is of paramount importance for the design energy of its implementation and evaluation of the system itself. This study aims to determine a relationship between the maximum power generated by solar photovoltaic and characteristic parameters of the generator. This relationship allows to evaluate the performance of such a system. For simulations of the developed equations were used 3 photovoltaic modules with an output of 100 Wp each, and data collection was performed during one year by enrolling in addition to meteorological data, solar irradiance incident on the modules.
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The use of alternative energy systems in the current days is an urgent necessity due to the problems that the planet is facing as the heating and loss of ozone layer. The scarcity of conventional energy is another problem that must be solved for the future of humanity. It must be considered that the people are inhabiting places moved away not always with available energy. The application of technologies as automation and control can help us to solve this problem. Therefore, this work aimed at apply an equipment of industrial usage, the Programmable Logical Controller, PLC, in alternative energies systems, as eolic generation and fotovoltaic generation used for water pumping, aiming the automatic control and the efficiency in the places where it has simultaneous availability of these sources, based in criterion of priority that previously established itself between them. It was made a hydraulic and energetic evaluation of the energy system, eolic and fotovoltaic, used in the automatic control system of pumping, in the place of accomplishment of the experiment, according to previously established physical conditions. The results have shown that the control system using the PLC is practicable and has trustworthiness. The program developed can be adapted for the use with several power plants in a specific application place. The fotovoltaic system of pumping, using a polycrystalline of 70 Watts connected to a pump Shurflo 8000, showed to be efficient with significant flows in almost all the months. The eolic system of pumping, using an eolic generator of 400 Watts assembled in place of experiment, did not demonstrate energetic capacity for use in this specific type of application.
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This work presents a study on the design of a photovoltaic system connected to the grid.It discussed the main characteristics of the solar cell which is the basic component for the manufacture of solar modulethe main components of the photovoltaic system and the steps of the photovoltaic and electrical design of the system, ranging from the choice of the photovoltaic module to the dimensioning of the components of the electrical installation.In addition to the technical design, this work contains a complete comparative analysis of the current situation of photovoltaic generation distributed in Brazil and Portugal, through incentive programs to energy use as well as current legislation in both countries
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This work presents a study on the design of a photovoltaic system connected to the grid.It discussed the main characteristics of the solar cell which is the basic component for the manufacture of solar modulethe main components of the photovoltaic system and the steps of the photovoltaic and electrical design of the system, ranging from the choice of the photovoltaic module to the dimensioning of the components of the electrical installation.In addition to the technical design, this work contains a complete comparative analysis of the current situation of photovoltaic generation distributed in Brazil and Portugal, through incentive programs to energy use as well as current legislation in both countries
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Este estudo teve como objetivo desenvolver uma metodologia de construção de um Painel de Monitoramento e Avaliação da Gestão do Sistema Único de Saúde (SUS). O processo participativo utilizado e a sistematização realizada permitiram identificar uma estratégia efetiva para a construção de instrumentos de gestão em parceria entre pesquisadores, instituições acadêmicas e gestores do SUS. A sistematização final do Painel selecionou indicadores da gestão do SUS em termos de Demandas, Insumos, Processos, Produtos e Resultados de forma a disponibilizar um instrumento simples, ágil e útil para a avaliação em qualquer instância de gestão e mais transparente e de mais fácil comunicação com todos os interessados na tomada de decisão. Tomar a gestão do SUS como objeto destes processos e práticas em seus aspectos normativos possibilitou o diálogo entre teorias sistêmicas e aquelas que consideram a centralidade do ator social no processo de tomada de decisão.
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O objetivo no estudo aqui apresentado foi identificar os fatores que determinam a divulgação voluntária ambiental pelas empresas brasileiras potencialmente poluidoras. Para tanto, foram analisa- das as Demonstrações Financeiras Padronizadas (DFPs) e os Relató- rios de Sustentabilidade (RS) do período de 2005 a 2007 das empresas abertas com ações listadas na Bolsa de Valores de São Paulo (Bovespa) e pertencentes a setores de alto impacto ambiental, que compreendem extração e tratamento de minerais; metalúrgico; químico; papel e celulose; indústria de couros e peles; transporte, terminais, depósitos e comércio (de combustíveis, derivados de petróleo e produtos químicos). Com o intuito de explicar a evidenciação ambiental divulgada pelas empresas investigadas, foram formuladas sete hipóteses testadas a partir de instrumentos de análise estatística. Essas hipóteses referem-se a fatores individuais das empresas, que englobam tamanho, rentabilidade, endividamento, empresa de auditoria, sustentabilidade, internacionalização e publicação do RS. Os resultados mostram que, nos três anos analisados, as 57 empresas que compõem a amostra do estudo evidenciaram um total de 6.182 sentenças ambientais, 73% delas divulgadas nos RS e 27% nas DFPs. A análise de regressão em painel demonstrou que as variáveis tamanho da empresa, empresa de auditoria, sustentabilidade e publicação do RS são relevantes a um nível de significância de 5% para a explicação do disclosure voluntário de informações ambientais. Concluiu-se que os achados da pesquisa corroboram a teoria positiva da contabilidade, e parcialmente a teoria da legitimidade.
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Modelos de apreçamento de ativos têm sido um tema sob constante investigação em finanças. Desde o capital asset pricing model (CAPM) proposto por Sharpe (1964), tais modelos relacionam, geralmente de maneira linear, a taxa de retorno esperada de um ativo ou carteira de ativos com fatores de risco sistêmico. Esta pesquisa apresenta um teste de um modelo de apreçamento, com dados brasileiros, introduzindo em sua formulação fatores de risco baseados em comomentos estatísticos. O modelo proposto é uma extensão do CAPM original acrescido da coassimetria e da cocurtose entre as taxas de retorno das ações das empresas que compõem a amostra e as taxas de retorno da carteira de mercado. Os efeitos de outras variáveis, como o valor de mercado sobre valor contábil, a alavancagem financeira e um índice de negociabilidade em bolsa, serviram de variáveis de controle. A amostra foi composta de 179 empresas brasileiras não financeiras negociadas na BM&FBovespa e com dados disponíveis entre os anos de 2003 a 2007. A metodologia consistiu em calcular os momentos sistêmicos anuais a partir de taxas de retornos semanais e em seguida testá-los em um modelo de apreçamento, a fim de verificar se há um prêmio pelo risco associado a cada uma dessas medidas de risco. Foi empregada a técnica de análise de dados em painel, estimada pelo método dos momentos generalizado (GMM). O emprego do GMM visa lidar com potenciais problemas de determinação simultânea e endogeneidade nos dados, evitando a ocorrência de viés nas estimações. Os resultados das estimações mostram que a relação das taxas de retorno dos ativos com a covariância e a cocurtose são estatisticamente significantes. Os resultados se mostraram robustos a especificações alternativas do modelo. O artigo contribui para a literatura por apresentar evidências empíricas brasileiras de que há um prêmio pelo risco associado aos momentos sistêmicos.