Desenvolvimento de tecnologia educacional para o uso racional de energia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Uso racional de energia elétrica na classe residencial: estudo de caso com alunos do ensino médio

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Aplicação e análise do uso racional de energia elétrica na Fazenda Experimental Lageado-UNESP, Botucatu-SP

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Avaliação do comportamento estrutural de subestações de energia elétrica com o uso do aço inoxidável.

A crescente utilização do aço inoxidável como elemento estrutural despertou o interesse de clientes, arquitetos e engenheiros nos últimos anos. Apesar do custo ainda elevado, a sua aplicação na construção civil vem substituindo outros elementos estruturais. Seja por sua alta resistência à corrosão, aumentando a relação custo benefício; sua estética, proporcionando formas cada vez mais ousadas ou; seu apelo ambiental, gerando menos resíduos no meio ambiente. As subestações representam um papel importante no fornecimento de energia. Como possuem grande complexidade para manutenção, foi escolhida a estrutura suporte de seu barramento, para o dimensionamento em aço inoxidável. Desta forma, minimizando as paradas para realização de manutenções das estruturas, possibilitando maior qualidade no fornecimento de energia elétrica. Para fins comparativos foi escolhido o projeto de uma SE existente, cuja estrutura de suporte do barramento, foi construída por treliças formadas por cantoneiras de aço carbono galvanizado. Inicialmente, o dimensionamento foi desenvolvido utilizando perfis H e I funcionando como viga-coluna para os dois tipos de aço. Num segundo momento, a estrutura foi dimensionada como treliças planas. Todos os dimensionamentos foram realizados de acordo com as prescrições normativas do EUROCODE 3. Após realização dos dimensionamentos, foram apresentadas as análises comparativas dos custos envolvidos para os tipos de aço. Abordando o investimento inicial, os gastos com manutenção ao longo da vida e os custos elétricos agregados à redução das paradas para manutenção.

Uso de técnicas de otimização baseadas em derivadas como suporte do planejamento operacional de redes de distribuição de energia elétrica

The usual programs for load flow calculation were in general developped aiming the simulation of electric energy transmission, subtransmission and distribution systems. However, the mathematical methods and algorithms used by the formulations were based, in majority, just on the characteristics of the transmittion systems, which were the main concern focus of engineers and researchers. Though, the physical characteristics of these systems are quite different from the distribution ones. In the transmission systems, the voltage levels are high and the lines are generally very long. These aspects contribute the capacitive and inductive effects that appear in the system to have a considerable influence in the values of the interest quantities, reason why they should be taken into consideration. Still in the transmission systems, the loads have a macro nature, as for example, cities, neiborhoods, or big industries. These loads are, generally, practically balanced, what reduces the necessity of utilization of three-phase methodology for the load flow calculation. Distribution systems, on the other hand, present different characteristics: the voltage levels are small in comparison to the transmission ones. This almost annul the capacitive effects of the lines. The loads are, in this case, transformers, in whose secondaries are connected small consumers, in a sort of times, mono-phase ones, so that the probability of finding an unbalanced circuit is high. This way, the utilization of three-phase methodologies assumes an important dimension. Besides, equipments like voltage regulators, that use simultaneously the concepts of phase and line voltage in their functioning, need a three-phase methodology, in order to allow the simulation of their real behavior. For the exposed reasons, initially was developped, in the scope of this work, a method for three-phase load flow calculation in order to simulate the steady-state behaviour of distribution systems. Aiming to achieve this goal, the Power Summation Algorithm was used, as a base for developing the three phase method. This algorithm was already widely tested and approved by researchers and engineers in the simulation of radial electric energy distribution systems, mainly for single-phase representation. By our formulation, lines are modeled in three-phase circuits, considering the magnetic coupling between the phases; but the earth effect is considered through the Carson reduction. It s important to point out that, in spite of the loads being normally connected to the transformer s secondaries, was considered the hypothesis of existence of star or delta loads connected to the primary circuit. To perform the simulation of voltage regulators, a new model was utilized, allowing the simulation of various types of configurations, according to their real functioning. Finally, was considered the possibility of representation of switches with current measuring in various points of the feeder. The loads are adjusted during the iteractive process, in order to match the current in each switch, converging to the measured value specified by the input data. In a second stage of the work, sensibility parameters were derived taking as base the described load flow, with the objective of suporting further optimization processes. This parameters are found by calculating of the partial derivatives of a variable in respect to another, in general, voltages, losses and reactive powers. After describing the calculation of the sensibility parameters, the Gradient Method was presented, using these parameters to optimize an objective function, that will be defined for each type of study. The first one refers to the reduction of technical losses in a medium voltage feeder, through the installation of capacitor banks; the second one refers to the problem of correction of voltage profile, through the instalation of capacitor banks or voltage regulators. In case of the losses reduction will be considered, as objective function, the sum of the losses in all the parts of the system. To the correction of the voltage profile, the objective function will be the sum of the square voltage deviations in each node, in respect to the rated voltage. In the end of the work, results of application of the described methods in some feeders are presented, aiming to give insight about their performance and acuity

Uso de técnicas de otimização baseadas em derivadas como suporte do planejamento operacional de redes de distribuição de energia elétrica

The usual programs for load flow calculation were in general developped aiming the simulation of electric energy transmission, subtransmission and distribution systems. However, the mathematical methods and algorithms used by the formulations were based, in majority, just on the characteristics of the transmittion systems, which were the main concern focus of engineers and researchers. Though, the physical characteristics of these systems are quite different from the distribution ones. In the transmission systems, the voltage levels are high and the lines are generally very long. These aspects contribute the capacitive and inductive effects that appear in the system to have a considerable influence in the values of the interest quantities, reason why they should be taken into consideration. Still in the transmission systems, the loads have a macro nature, as for example, cities, neiborhoods, or big industries. These loads are, generally, practically balanced, what reduces the necessity of utilization of three-phase methodology for the load flow calculation. Distribution systems, on the other hand, present different characteristics: the voltage levels are small in comparison to the transmission ones. This almost annul the capacitive effects of the lines. The loads are, in this case, transformers, in whose secondaries are connected small consumers, in a sort of times, mono-phase ones, so that the probability of finding an unbalanced circuit is high. This way, the utilization of three-phase methodologies assumes an important dimension. Besides, equipments like voltage regulators, that use simultaneously the concepts of phase and line voltage in their functioning, need a three-phase methodology, in order to allow the simulation of their real behavior. For the exposed reasons, initially was developped, in the scope of this work, a method for three-phase load flow calculation in order to simulate the steady-state behaviour of distribution systems. Aiming to achieve this goal, the Power Summation Algorithm was used, as a base for developping the three phase method. This algorithm was already widely tested and approved by researchers and engineers in the simulation of radial electric energy distribution systems, mainly for single-phase representation. By our formulation, lines are modeled in three-phase circuits, considering the magnetic coupling between the phases; but the earth effect is considered through the Carson reduction. Its important to point out that, in spite of the loads being normally connected to the transformers secondaries, was considered the hypothesis of existence of star or delta loads connected to the primary circuit. To perform the simulation of voltage regulators, a new model was utilized, allowing the simulation of various types of configurations, according to their real functioning. Finally, was considered the possibility of representation of switches with current measuring in various points of the feeder. The loads are adjusted during the iteractive process, in order to match the current in each switch, converging to the measured value specified by the input data. In a second stage of the work, sensibility parameters were derived taking as base the described load flow, with the objective of suporting further optimization processes. This parameters are found by calculating of the partial derivatives of a variable in respect to another, in general, voltages, losses and reactive powers. After describing the calculation of the sensibility parameters, the Gradient Method was presented, using these parameters to optimize an objective function, that will be defined for each type of study. The first one refers to the reduction of technical losses in a medium voltage feeder, through the installation of capacitor banks; the second one refers to the problem of correction of voltage profile, through the instalation of capacitor banks or voltage regulators. In case of the losses reduction will be considered, as objective function, the sum of the losses in all the parts of the system. To the correction of the voltage profile, the objective function will be the sum of the square voltage deviations in each node, in respect to the rated voltage. In the end of the work, results of application of the described methods in some feeders are presented, aiming to give insight about their performance and acuity

Racionalização da energia elétrica com aplicação da legislação tarifária em indústria de embalagem plástica

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Programa computacional para análise do faturamento do consumo de energia elétrica através do k-hiperbolóide de carga e potência em empresas frigoríficas abatedoras de bovinos

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Um framework para a previsão de cenários com o uso de sistemas híbridos neurogenéticos para compra e venda de energia elétrica no mercado futuro

No contexto da previsão de séries temporais, é grande o interesse em estudos de métodos de previsão de séries temporais que consigam identificar as estruturas e padrões existentes nos dados históricos, possibilitando gerar os próximos padrões da série. A proposta defendida nesta tese é a de desenvolvimento de um framework que utilize ao máximo as potencialidades das técnicas de previsão (redes neurais artificiais) com as técnicas de otimização (algoritmos genéticos) em um sistema híbrido intercomunicativo que aproveite bem as vantagens de cada uma dessas técnicas para a geração de cenários futuros que possam mostrar, além das previsões normais com base nos valores históricos, percursos alternativos das curvas das séries temporais analisadas.

Uso do ATP para simulações de descargas atmosféricas em para-raios de 15 kV dos serviços auxiliares de subestações de energia elétrica

This paper addresses the topics required for the selection of surge arresters used, the output of autotransformers, which protect the system Auxiliary Services (SE) of an electrical substation. Surge arresters used are part of the Protection System Lightning (SPDA). Transmission lines mostly run through regions with orographic well diversified and have constant weather changes, which lead to many undesirable interactions with electromagnetic phenomena, such as giving rise to blackout on 10 November 2009, which left nine states without power, which led to unplanned shutdowns in the system that left millions of people without electricity. This work of completion is to determine whether the method used in the selection of surge arresters meet the protection needs faced by a substation auxiliary services, through the use of software use ATPDraw

Análise do faturamento de consumo de energia elétrica para uma usina de açúcar e álcool

O presente trabalho demonstra por meio da estatística descritiva a situação de faturamento de energia elétrica de uma usina de açúcar e álcool da região de Quatá. Com o intuito de avaliar a utilização da energia elétrica da usina, foram descritos os fatores que interferem no uso da energia elétrica, dados pelo fator de carga (fc) e fator de potência (fp). Nesse trabalho optamos pela estatística descritiva, cujo objetivo básico é o de sintetizar uma série de valores de mesma natureza, permitindo dessa forma que se tenha uma visão global da variação desses valores, organizando e descrevendo os dados de três maneiras: por meio de tabelas, de gráficos e de medidas descritivas. Foi elaborada uma planilha com a média de todos os meses dos anos de 2008 a 2010 a partir dos dados fornecidos pela concessionária de energia elétrica. Foi verificado que a empresa é extremamente eficiente, fato verificado durante estes três anos pela avaliação do fator de potência que geralmente foi 1,0. A empresa foi em média considerada racional, pois seu fator de carga calculado foi avaliado como regular nestes 3 anos.

A participação dos medidores eletrônicos na rede inteligente de energia elétrica

Depuis que l'électricité a été découverte et que le secteur électrique s'est considérablement développé dans le XVIIIe siècle, jamais l'homme n'a pu se détacher de cette énergie. Pendant longtemps le système d'énergie électrique a fonctionné sans grand changement, mais avec le développement rapide des technologies, de nouvelles améliorations apparaissent. Ce mémoire traite des nouveaux concepts de réseaux d'énergie électrique appelés Réseaux intelligents ou Smart Grid. À travers un panorama de leurs développements dans le monde, cette étude porte d'une part, sur l'avancée des projets dans quelques pays et d'autre part, du niveau de développement de ce réseau au Brésil et de son intérêt pour le pays. L'étude a comme point central un des composants de ce réseau intelligent, le compteur communicant, qui est l'élément essentiel des interconnexions entre consommateurs et producteurs. Ce rapport apporte un éclaircissement sur les compteurs conventionnels et les compteurs intelligents et sur leur mode de fonctionnement. Enfin il aborde la question des consommateurs : par quels moyens leur transmettre tous ces changements à venir, puisque jusqu'à présent, leur seule participation était de payer l'énergie consommée. Avec le nouveau réseau, ils deviendront de véritables acteurs puisqu'ils seront informés en temps réel de leur consommation d'énergie électrique. Pour terminer, le mémoire montrera comment ils pourront s'adapter à cette nouvelle façon de gérer leur consommation en ésperant les inciter à une utilisation plus raisonnable de l'énergie et à modifier leur comportement en gérant de manière active leur consommation en intégrant notamment les énergies renouvelables

A participação dos medidores eletrônicos na rede inteligente de energia elétrica

Depuis que l'électricité a été découverte et que le secteur électrique s'est considérablement développé dans le XVIIIe siècle, jamais l'homme n'a pu se détacher de cette énergie. Pendant longtemps le système d'énergie électrique a fonctionné sans grand changement, mais avec le développement rapide des technologies, de nouvelles améliorations apparaissent. Ce mémoire traite des nouveaux concepts de réseaux d'énergie électrique appelés Réseaux intelligents ou Smart Grid. À travers un panorama de leurs développements dans le monde, cette étude porte d'une part, sur l'avancée des projets dans quelques pays et d'autre part, du niveau de développement de ce réseau au Brésil et de son intérêt pour le pays. L'étude a comme point central un des composants de ce réseau intelligent, le compteur communicant, qui est l'élément essentiel des interconnexions entre consommateurs et producteurs. Ce rapport apporte un éclaircissement sur les compteurs conventionnels et les compteurs intelligents et sur leur mode de fonctionnement. Enfin il aborde la question des consommateurs : par quels moyens leur transmettre tous ces changements à venir, puisque jusqu'à présent, leur seule participation était de payer l'énergie consommée. Avec le nouveau réseau, ils deviendront de véritables acteurs puisqu'ils seront informés en temps réel de leur consommation d'énergie électrique. Pour terminer, le mémoire montrera comment ils pourront s'adapter à cette nouvelle façon de gérer leur consommation en ésperant les inciter à une utilisation plus raisonnable de l'énergie et à modifier leur comportement en gérant de manière active leur consommation en intégrant notamment les énergies renouvelables

Redes de energia elétrica inteligentes (smart grids)

Trecho da Nota Técnica: "Com o avanço do uso da tecnologia digital nos sistemas de fornecimento de energia elétrica, começa a surgir o que se convencionou chamar de quarta geração desses sistemas, ou seja, as chamadas smart grids, caracterizadas pelo uso intensivo de equipamentos digitais, de telecomunicações, de sensoriamento e operação remotos de instalações, e de tecnologia de informação (TI), adicionalmente às instalações físicas de geração, transmissão e distribuição de energia elétrica existentes." Consultoria Legislativo - Área XII Recursos Minerais, Hídricos e Energéticos.