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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Proposta de norma de conexão de fontes de geração distribuída à rede de baixa tensão da concessionária / Proposal of standard connection for distributed generation sources on low voltage network of the utility

Donadon, Antonio Roberto 16 August 2018 (has links)
Orientadores: João Carlos Camargo, Ennio Peres da Silva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica e Instituto de Geociências / Made available in DSpace on 2018-08-16T18:59:48Z (GMT). No. of bitstreams: 1 Donadon_AntonioRoberto_M.pdf: 1117953 bytes, checksum: 01a83592806648f889aea2c35b02b7c6 (MD5) Previous issue date: 2010 / Resumo: O objetivo do trabalho foi propor uma minuta de norma de conexão de geradores ou pequenos sistemas de geração distribuída em baixa tensão (GDBT) com potência menor ou igual a 75 kW monofásico ou trifásico com conversão estática em paralelo com a rede de distribuição secundária da concessionária local. Para atingir esse objetivo realizou-se um levantamento do estado da arte em matéria de normas de conexão em países onde esse assunto já se encontra em situação mais avançada bem como da incipiente legislação brasileira sobre o assunto. Baseado nisso e nos os dados obtidos dos testes de operação das fontes estudadas no projeto de pesquisa Implantação de Geração Distribuída Junto à Rede de Distribuição relacionados aos aspectos de qualidade de energia e segurança chegou-se a um elenco de tópicos relevantes para a construção de uma norma. O trabalho concluiu também que fontes de GDBT que possuam conversores estáticos que atendam aos requisitos de segurança e qualidade de energia da norma internacional IEEE 1547 poderiam ser conectadas à rede de distribuição da concessionária / Abstract: The objective was to propose a draft standard for connecting small single-phase or three phase generators with rated power lower than or equal to 75 kW with static converter in parallel with low voltage utility grid (GDBT). To reach this goal it was carried out a survey of the state of the art in connection standards in countries where this matter is already more advanced state as well as the incipient Brazilian legislation on this matter. Based on this survey and the data obtained from operation tests of power sources studied in the R&D project Implementation of Distributed Generation in the Utility Grid related to safety and power quality was possible to obtain a range of relevant topics to build a connection standard. The study also concluded that GDBT power sources equipped with static converters that meet the international standard IEEE 1547 safety and power quality requirements could be connected to the utility grid / Mestrado / Engenharia Mecanica / Mestre em Planejamento de Sistemas Energéticos
12

Os contratos de comercialização de energia elétrica: uma análise sob o prisma do direito civil / Agreements for the commercialization of electrical energy: an analisys under the Civil Law.

Ueda, Andréa Silva Rasga 13 February 2015 (has links)
O presente trabalho objetiva tratar a comercialização da energia elétrica sob a visão do direito civil, uma vez que esse assunto tem ficado restrito aos campos do direito administrativo, regulatório ou econômico. Por ser a energia elétrica um bem, dotado de valoração econômica, conforme inciso I do artigo 83 do Código Civil, entendemos ser o momento de o jurista civilista olhar para o contrato largamente usado no Ambiente de Contratação Livre e, a partir de então, avaliar se a estrutura ou natureza jurídica atualmente usada pode ser entendida como um típico contrato de compra e venda, ou se guarda correlação com outros tipos contratuais, bem como se ainda existem lacunas ou brechas que podem ser ajustadas por meio da teoria das obrigações e dos contratos. Partiremos de uma análise da energia elétrica enquanto bem móvel, diante dos atuais enquadramentos legais da mesma sob os aspectos penais, tributários e constitucionais nacionais, e adentraremos no estudo dos princípios contratuais a fim de verificar sua aplicação no atual modelo de contrato de comercialização de energia no ambiente livre. Delimitado o objeto do estudo, a segunda etapa será o ponto central do trabalho, quando deitaremos olhos sobre um modelo padrão de contrato de comercialização de energia elétrica, com a intenção de trazer novas luzes a essa relação contratual, com respaldo na teoria das obrigações e dos contratos do direito civil brasileiro. Após essas análises, finalizaremos o trabalho trazendo subsídios para avaliar como o direito civil lida com a energia elétrica, um bem imaterial de produção e consumo imediatos, como permite sua comercialização e o que se conserva desse ramo do direito em um tema mergulhado no âmbito regulado. / This thesis aims to treat the sale of electrical energy under the vision of private law, since this subject has been restricted to the administrative, regulatory or economic law. In virtue of the economic valuation of the electrical energy, which is a good, according to item I of Article 83 of the Brazilian Civil Code, we believe that it is time for the civilian lawyers look at the contract widely used in the free market and then analyze if the current judicial structure or nature can be understood as a typical sale and purchase agreement or whether it has some elements of other types of contract, as well as if there are still gaps that can be adjusted through the theory of obligations and contracts. We will start the analysis of electrical energy as a movable good, using the current criminal, tax and constitutional legal dispositions about it. We will also study the contractual principles in order to analyze their application to the current model of energy trading contract in the free market. From this point, the second step will be the central investigation of this paper, when we will analyze a standard contract model used for the commercialization of electrical energy, with the intention of bringing new lights under this contractual relationship, based on the theory of obligations and contracts of the Brazilian private law. After these analyses, we will finish this paper bringing some points of view in order to evaluate how private law deals with electrical energy a production and immediate consumption immovable good , how it permits its commercialization and what is preserved from private law on a subject steeped in a regulated area.
13

Saving Electrical Energy in Commercial Buildings

Case, Ryan January 2012 (has links)
With the commercial and institutional building sectors using approximately 29% and 34% of all electrical energy consumption in Canada and the United States, respectively, saving electrical energy in commercial and institutional buildings represents an important chal- lenge for both the environment and the energy consumer. Concurrently, a rapid decline in the cost of microprocessing and communication has enabled the profileration of smart me- ters, which allow a customer to monitor energy usage every hour, 15 minutes or even every minute. Algorithmic analysis of this stream of meter readings would allow 1) a building operator to predict the potential cost savings from implemented energy savings measures without engaging the services of an expensive energy expert; and 2) an energy expert to quickly obtain a high-level understanding of a building’s operating parameters without a time-consuming and expensive site visit. This thesis develops an algorithm that takes as input a stream of building meter data and outputs a building’s operating parameters. This output can be used directly by an energy expert to assess a building’s performance; it can also be used as input to other algorithms or systems, such as systems that 1) predict the cost savings from a change in these operating parameters; 2) benchmark a portfolio of building; 3) create baseline models for measurement and verification programs; 4) detect anomalous building behaviour; 5) provide novel data visualization methods; or 6) assess the applicability of demand response programs on a given building. To illustrate this, we show how operating parameters can be used to estimate potential energy savings from energy savings measures and predict building energy consumption. We validate our ap- proach on a range of commercial and institutional buildings in Canada and the United States; our dataset consists of 10 buildings across a variety of geographies and industries and comprises over 21 years of meter data. We use K-fold cross-validation and benchmark our work against a leading black-box prediction algorithm; our model offers comparable prediction accuracy while being far less complex.
14

Saving Electrical Energy in Commercial Buildings

Case, Ryan January 2012 (has links)
With the commercial and institutional building sectors using approximately 29% and 34% of all electrical energy consumption in Canada and the United States, respectively, saving electrical energy in commercial and institutional buildings represents an important chal- lenge for both the environment and the energy consumer. Concurrently, a rapid decline in the cost of microprocessing and communication has enabled the profileration of smart me- ters, which allow a customer to monitor energy usage every hour, 15 minutes or even every minute. Algorithmic analysis of this stream of meter readings would allow 1) a building operator to predict the potential cost savings from implemented energy savings measures without engaging the services of an expensive energy expert; and 2) an energy expert to quickly obtain a high-level understanding of a building’s operating parameters without a time-consuming and expensive site visit. This thesis develops an algorithm that takes as input a stream of building meter data and outputs a building’s operating parameters. This output can be used directly by an energy expert to assess a building’s performance; it can also be used as input to other algorithms or systems, such as systems that 1) predict the cost savings from a change in these operating parameters; 2) benchmark a portfolio of building; 3) create baseline models for measurement and verification programs; 4) detect anomalous building behaviour; 5) provide novel data visualization methods; or 6) assess the applicability of demand response programs on a given building. To illustrate this, we show how operating parameters can be used to estimate potential energy savings from energy savings measures and predict building energy consumption. We validate our ap- proach on a range of commercial and institutional buildings in Canada and the United States; our dataset consists of 10 buildings across a variety of geographies and industries and comprises over 21 years of meter data. We use K-fold cross-validation and benchmark our work against a leading black-box prediction algorithm; our model offers comparable prediction accuracy while being far less complex.
15

Ανάπτυξη μεθόδων βέλτιστου ελέγχου και ανατροφοδότησης εξόδου με εφαρμογές στα συστήματα ηλεκτρικής ενέργειας

Ηρακλέους, Δημήτριος 16 November 2009 (has links)
- / -
16

L'efficacité d'usage énergétique : pour une meilleure gestion de l'énergie électrique intégrant l'usager dans les bâtiments / Use Energy Efficiency for better energy managment integrating user in buildings

Chenailler, Hervé 17 April 2012 (has links)
La consommation énergétique, et en particulier électrique, des bâtiments est grandement influencée par le comportement de ses usagers. L'analyse de l'usage électrique au travers d'un retour d'expérience réalisé sur une plateforme bâtiment-test nous a permis d'identifier qu'il pouvait exister différentes formes de satisfactions des usagers remettant en question la notion même d'efficacité énergétique d'un bâtiment. Afin de pouvoir intégrer l'acteur humain dans la conception de systèmes complexes bâtiment, nous proposons de définir la notion d'efficacité énergétique d'usage (EUE). Cette notion repose en particulier sur la satisfaction des usagers vis à vis d'un service que l'on a pu décomposer et quantifier au travers de fonctions de satisfaction rationnelles et sensibles. Le but de cette proposition est la construction d'un diagramme de compromis Coût / Satisfaction qui se positionne à la fois comme un outil effectif d'aide à la décision pour la conception de systèmes énergétiques du bâtiment intégrant l'usager et comme outil d'aide à la sobriété énergétique. / Energy consumption, particularly electric consumption, in buildings is greatly influenced by the behavior of its occupants. The analysis of the electrical uses thanks to a feedback performed on a test-building platform makes it possible to identify different forms of user satisfaction calling into question the notion of energy efficiency in buildings. In order to take into account the human actors in the design of building systems, it is proposed to define the notion of energy use efficiency (EUE). This notion is based on the user satisfaction about services that has been split and quantified as rational and sensitive satisfaction functions. This notion led to the construction of a cost / satisfaction compromise diagram, which is an effective tool for decision support during the design of building energy systems taking into account the occupants but also a support tool for energy sobriety during operation.
17

Úspory energie při modernizaci PC sítě / Reduction in the Consumption of Electrical Energy during Computer Network

Doležal, Michal January 2010 (has links)
This Master’s thesis deals with the analysis problem during of electrical energy. On the basis of findings, the work includes analysis of the costs on electrical energy.
18

Semiconducting tin oxide and cobalt oxide films for future solar energy applications

Carroll, Alan F. 08 June 2010 (has links)
Increased need for alternative energy sources has instigated much interest in conversion of solar energy to other useful forms of energy. Semiconducting oxide thin films have potential applicability in photovoltaic conversion of solar energy to electrical energy and thermal energy collection or reflection. Pyrolytic thin films of Sn02-x and r. f. sputtered thin films of CoOx were prepared in this study and analyzed for electrical, optical,and structural characteristics. The experimental techniques used for this investigation were X-ray diffraction, visible and infrared spectrometry, electron spectroscopy for chemical analysis, scanning electron microscopy, heat treatment, and electrical resistivity measurement carried out at different temperatures. The information obtained from this investigation has shed new light on the cause for conductivity in SnO 20-Z. Chlorine impurity atoms were found ~o remain in the film due to incomplete pyrolytic decomposition. Of great interest was the finding that this chlorine was not affected by annealing of the films. Resistivity increases caused by annealing were shown to arise from film oxidation and interdiffusion of film with glass substrate. / Master of Science
19

Estudo de controle e proteção para sistemas de transmissão HVDC multiterminais baseados em conversores modulares multiní­veis. / Control and protection study of multiterminal HVDC transmission systems based on modular multilevel converters.

Suzuki, Nayara Yuko 28 June 2018 (has links)
O crescente interesse por sistemas de transmissão do tipo VSC-based HVDC (VSCHVDC) como alternativa aos atuais tem levado à necessidade de estudos sobre o principal desafio associado à sua implantação, que é o desenvolvimento de um esquema de proteção que seja rápido e que identifique a zona de proteção na qual uma eventual falta tenha ocorrido, respeitando-se assim o princípio de seletividade. Para estudo de um sistema de proteção que atenda a estes requisitos, foi utilizada neste trabalho uma rede com quatro terminais e transmissão High-Voltage Direct Current (HVDC), implementada com conversores modulares multiníveis (Modular Multilevel Converter (MMC)) e simulada em situações de contingência. Grandezas medidas nos elos de Corrente Contínua (CC) ligados a um dos terminais foram utilizadas para identificar a ocorrência de uma contingência na rede e então para decidir se trata-se de uma falta interna à zona de proteção considerada na análise. Para classificar as faltas em interna ou externa, observaram-se os espectros dos sinais de tensão CC em um terminal, calculados sobre uma janela do sinal através de Fast Fourier Transform (FFT), para várias situações de falta. Destes espectros, notou-se que uma característica varia de acordo com a distância da falta até o terminal, com o fato de a falta ser interna ou externa e com a resistência de falta. Através desta característica, denominada aqui \"frequência de centro de massa\", foi possível distinguir as faltas internas com resistências de falta baixas do restante dos eventos testados. Considerando-se apenas este parâmetro, não foi possível classificar corretamente faltas internas com resistência de falta muito alta. / The growing interest in VSC-based HVDC (VSC-HVDC) transmission systems as an alternative to the current ones has required studies about the the main challenge associated with its application, which is the development of a protection scheme that is able to both fast and efficiently determine the protection zone where a fault may have happened so as to achieve selectivity. In order to study a protection system that complies with those requirements, a High-Voltage Direct Current (HVDC) transmission system with four terminals implemented with Modular Multilevel Converter (MMC) converters was simulated under contingency condition. Electrical quantities measured in one of the terminal\'s Direct Current (DC) links were used to determine the occurrence of a fault event in the system, as well as to decide whether that event belonged to the protection zone considered in the analysis. Spectra obtained via Fast Fourier Transform (FFT) over a window of the DC voltage measured in one of the terminals were observed in order to discriminate between internal and external fault events. From these observations, it was noticed that a certain characteristic, named here \"center of mass frequency\", varies according to the distance between the fault location and the terminal, fault resistance, as well as whether that the fault is either internal or external to the analysed protection zone. By using this characteristic, it was possible to tell internal faults with low resistance fault from other events. Considering this parameter only, it was not possible to correctly classify internal faults with high fault resistance.
20

Estudo de controle e proteção para sistemas de transmissão HVDC multiterminais baseados em conversores modulares multiní­veis. / Control and protection study of multiterminal HVDC transmission systems based on modular multilevel converters.

Nayara Yuko Suzuki 28 June 2018 (has links)
O crescente interesse por sistemas de transmissão do tipo VSC-based HVDC (VSCHVDC) como alternativa aos atuais tem levado à necessidade de estudos sobre o principal desafio associado à sua implantação, que é o desenvolvimento de um esquema de proteção que seja rápido e que identifique a zona de proteção na qual uma eventual falta tenha ocorrido, respeitando-se assim o princípio de seletividade. Para estudo de um sistema de proteção que atenda a estes requisitos, foi utilizada neste trabalho uma rede com quatro terminais e transmissão High-Voltage Direct Current (HVDC), implementada com conversores modulares multiníveis (Modular Multilevel Converter (MMC)) e simulada em situações de contingência. Grandezas medidas nos elos de Corrente Contínua (CC) ligados a um dos terminais foram utilizadas para identificar a ocorrência de uma contingência na rede e então para decidir se trata-se de uma falta interna à zona de proteção considerada na análise. Para classificar as faltas em interna ou externa, observaram-se os espectros dos sinais de tensão CC em um terminal, calculados sobre uma janela do sinal através de Fast Fourier Transform (FFT), para várias situações de falta. Destes espectros, notou-se que uma característica varia de acordo com a distância da falta até o terminal, com o fato de a falta ser interna ou externa e com a resistência de falta. Através desta característica, denominada aqui \"frequência de centro de massa\", foi possível distinguir as faltas internas com resistências de falta baixas do restante dos eventos testados. Considerando-se apenas este parâmetro, não foi possível classificar corretamente faltas internas com resistência de falta muito alta. / The growing interest in VSC-based HVDC (VSC-HVDC) transmission systems as an alternative to the current ones has required studies about the the main challenge associated with its application, which is the development of a protection scheme that is able to both fast and efficiently determine the protection zone where a fault may have happened so as to achieve selectivity. In order to study a protection system that complies with those requirements, a High-Voltage Direct Current (HVDC) transmission system with four terminals implemented with Modular Multilevel Converter (MMC) converters was simulated under contingency condition. Electrical quantities measured in one of the terminal\'s Direct Current (DC) links were used to determine the occurrence of a fault event in the system, as well as to decide whether that event belonged to the protection zone considered in the analysis. Spectra obtained via Fast Fourier Transform (FFT) over a window of the DC voltage measured in one of the terminals were observed in order to discriminate between internal and external fault events. From these observations, it was noticed that a certain characteristic, named here \"center of mass frequency\", varies according to the distance between the fault location and the terminal, fault resistance, as well as whether that the fault is either internal or external to the analysed protection zone. By using this characteristic, it was possible to tell internal faults with low resistance fault from other events. Considering this parameter only, it was not possible to correctly classify internal faults with high fault resistance.

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