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Metodologia para avaliação e otimização de motores elétricos de indução trifásicos visando a conservação de energia em aplicações industriais; Methodology for evaluation and optimization of three-phase induction motors to promote the conservation of energy in industrial applications.

Ramos, Mario Cesar do Espirito Santo
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 29/10/2009 PT
Relevância na Pesquisa
46.17%
Esta tese apresenta uma metodologia específica para a quantificação das perdas energéticas em motores elétricos de indução trifásicos com rotor em gaiola, por meio da determinação indireta do rendimento nas condições de funcionamento a plena carga. A referida metodologia, denominada MHmit, foi desenvolvida em ambientes industriais, particularmente no segmento alimentício, contando também com a colaboração do Laboratório de Máquinas Elétricas do Instituto de Eletrotécnica e Energia da Universidade de São Paulo no tocante a disponibilização dos ensaios de vários motores de indução trifásicos com rotor em gaiola ao longo de vários anos de prestação de serviços. Esses ensaios foram de extrema importância para a validação da metodologia apresentada. Sendo o motor elétrico um equipamento de uso final de forte presença industrial, é passível de substituição por tecnologias mais eficientes mediante a realização de estudos de eficiência energética. Os diagnósticos energéticos em sistemas motrizes beneficiam as indústrias por meio da diminuição dos custos com energia elétrica, tanto pela redução de demanda, quanto pela redução do consumo. Porém, para o desenvolvimento desta metodologia foi necessária a avaliação de estudos realizados por empresas prestadoras de serviços na área de conservação de energia elétrica. Essas empresas foram selecionadas a partir da averiguação da satisfação do cliente quanto aos serviços prestados e resultados obtidos após a substituição dos motores. Por meio da análise de 266 casos...

Selective current compensators based on the conservative power theory

Paredes, Helmo K. M.; Marafão, Fernando P.; Da Silva, Luiz C. P.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
55.98%
This paper presents possible selective current compensation strategies based on the Conservative Power Theory (CPT). This recently proposed theory, introduces the concept of complex power conservation under non-sinusoidal conditions. Moreover, the related current decompositions results in several current terms, which are associated with a specific physical phenomena (power absorption P, energy storage Q, voltage and current distortion D). Such current components are used in this work for the definition of different current compensators, which can be selective in terms of minimizing particular disturbing effects. The choice of one or other current component for compensation directly affects the sizing and cost of active and/or passive devices and it will be demonstrated that it can be done to attend predefined limits for harmonic distortion, unbalances and/or power factor. Single-phase compensation strategies will be discussed by means of the CPT and simulation results will demonstrate their performance. © 2009 IEEE.

Conservação de energia no setor comercial : um novo negocio para as concessionarias de energia eletrica; Electric energy conservation in the commercial sector : a new business for the eletric concessionaries

Evandro Gustavo Romanini
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 30/10/2002 PT
Relevância na Pesquisa
56.12%
Neste trabalho, procurou-se estudar as novas oportunidades de negócios que as concessionárias de distribuição de energia elétrica vêm desenvolvendo, junto aos seus clientes comerciais. Para esta análise, foi necessário conhecer o atual cenário do mercado de energia no país e as novas leis sobre o Mercado Atacadista de Energia. Foram analisados os impactos da comercialização de energia com a abertura do mercado, da criação dos consumidores livres e do potencial de negócios na conservação de energia. Na conclusão, analisou-se o novo cenário de comercialização de energia e o potencial de ganho, financeiro e de marketing, das concessionárias de energia elétrica; The aim of this work is to study the new business opportunities that electric power utilities have been offering their commercial customers. To carry out this analysis, it was necessary to get information about the current conditions of the power market in this country and the new laws about the energy Wholesale Market. The impact of the market opening on the energy trade, the creation of free consumers, and the new prospects for the conservation of energy have been analyzed. At the conc1usion, the new setting for the energy trade and the prospects for marketing and financia! gains of the electric power concessionaires have been analyzed

Conservação de energia em edificios comerciais atraves da implementação de dispositivos de automação; Conservation of energy in commercial buildngs through the implementation of automation devices

Marcone Susumo Gomazako
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 23/10/2007 PT
Relevância na Pesquisa
66.01%
Este trabalho vem apresentar um panorama do sistema elétrico geralmente encontrado em construções comerciais de grande porte, com cerca de trinta anos de funcionamento, que operam de forma pouco eficiente para os parâmetros atuais, principalmente no seu sistema de ar condicionado central. Nessa construção (estudo), seu sistema de condicionamento ambiental representa um acréscimo na demanda energética de cerca de 60%, passando de 450.000 kWh/mês para 750.000 kWh/mês, e a troca desses equipamentos por mais modernos e eficientes, significaria grandes investimentos, tornando-se inviável no curto prazo. Com isso, elaborou-se um protótipo contendo dispositivos de automação, que podem ser incorporados ao sistema existente, sem grandes dificuldades, e minimizando os custos operacionais com o sistema. Esses dispositivos permitem um monitoramento mais eficiente, sem a necessidade desses investimentos, como a substituição de grandes equipamentos (compressores, chillers, etc.) que fazem parte do sistema de ar condicionado central. Esse protótipo permitiu demonstrar que com a aplicação desses dispositivos incorporados nesses sistemas, podem gerar uma economia de cerca de 20% no consumo de energia elétrica, que representa uma economia bastante significativa de 60.000 kWh/mês (neste caso) quando operado o sistema de ar condicionado...

Analise de diferentes tecnologias de iluminação artificial para redução do consumo de energia eletrica na produção de mudas de crisantemos em ambiente protegido; Analysis of different artificial illumination technologies aiming energy consumption reduction in chrysanthemum nursey production in greenhouses

Eduardo David
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 24/02/2007 PT
Relevância na Pesquisa
55.98%
No cultivo de crisântemos em ambientes protegidos, o tipo de iluminação artificial usada atualmente para propósito de indução do efeito de fotoperíodo determina o crescimento e desenvolvimento destas plantas cultivadas, bem como o consumo de energia elétrica utilizada no processo de produção. A tecnologia de iluminação artificial mais utilizado pelos produtores de mudas de crisântemos para efeito de indução de fotoperíodo é a de filamento incandescente. Atualmente, procura-se testar novas tecnologias de iluminação artificial visando principalmente à redução do consumo de energia elétrica. A aplicação da tecnologia de iluminação do tipo descarga (vapor de sódio, vapor de mercúrio, fluorescentes tubulares e fluorescentes compactas integradas), diferente da do tipo filamento, no cultivo de crisântemos em ambiente protegido foi o objetivo deste trabalho de pesquisa. Este trabalho foi realizado em uma casa de vegetação comercial com cinco variedades (Papiro, Lindy White, Mona Lisa Rose, Euro Speedy e Stateman), em dois períodos, verão e inverno. Os parâmetros utilizados para a comparação entre as variedades cultivadas foram a produtividade por área, o peso de matéria fresca, a presença de botão floral e a porcentagem de umidade. Para as diferentes tecnologias de iluminação e tipos de lâmpadas analisadas...

Modeling, characterization, and optimization of web server power in data centers = : Modelagem, caracterização e otimização de potência em centro de dados; Modelagem, caracterização e otimização de potência em centro de dados

Leonardo de Paula Rosa Piga
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 08/11/2013 PT
Relevância na Pesquisa
55.9%
Para acompanhar uma demanda crescente pelos recursos computacionais, empresas de TI precisaram construir instalações que comportam centenas de milhares de computadores chamadas centro de dados. Este ambiente é altamente dependente de energia elétrica, um recurso que é cada vez mais caro e escasso. Neste contexto, esta tese apresenta uma abordagem para otimizar potência e desempenho em centro de dados Web. Para isto, apresentamos uma infraestrutura para medir a potência dissipada por computadores de prateleiras, desenvolvemos modelos empíricos que estimam a potência de servidores Web e, por fim, implementamos uma de nossas heurísticas de otimização de potência global em um aglomerado de nós de processamento chamado AMD SeaMicro SM15k. A infraestrutura de medição de potência é composta por: uma placa personalizada, que é capaz de medir potência e é instalada em computadores de prateleira; um conversor de dados analógico/digital que amostra os valores de potência; e um software controlador. Mostramos uma nova metodologia para o desenvolvimento de modelos de potência para servidores Web que diminuem a quantidade de parâmetros dos modelos e reduzem as relações não lineares entre medidas de desempenho e potência do sistema. Avaliamos a nossa metodologia em dois servidores Web...

Modeling of electric power demand growth

Woodard, James B.; Baughman, Martin L.; Schweppe, Fred C.
Fonte: MIT Energy Lab Publicador: MIT Energy Lab
Tipo: Relatório Formato: 1495914 bytes; application/pdf
EN_US
Relevância na Pesquisa
55.92%
Paper given at MIT conference entitled Energy: Demand, Conservation and Institutional Problems, February 12-15, 1973

An environmental and economic comparison of cooling system designs for steam-electric power plants

Najjar, Kenneth F.; Shaw, John J.; Adams, E. Eric; Jirka, Gerhard H.; Harleman, Donald
Fonte: MIT Energy Laboratory Publicador: MIT Energy Laboratory
Tipo: Relatório Formato: 8009419 bytes; application/pdf
EN_US
Relevância na Pesquisa
55.96%
The selection of waste heat rejection systems for steam-electric power plants involves a trade-off among environmental, energy and water conservation, and economic factors. This study compares four general types of cooling systems on the basis of these factors. The cooling systems chosen for study are: once-through systems including surface canals and submerged multiport diffusers; shallow closed cycle cooling ponds; mechanical and natural draft evaporative cooling towers; and mechanical draft dry towers. The cooling system comparison involves, first, an optimization of each cooling system and then a comparison among optimal systems. Comparison is made for an 800 MWe fossil unit and a 1200 MWe nuclear unit located at a hypothetical midwestern river site. A set of models has been developed to optimize the components of each cooling system based on the local meteorological and hydrological conditions at the site in accordance with a fixed demand, scalable plant concept. This concept allows one to compare the costs of producing the same net power from each plant/cooling system. Base case economic parameters were used to evaluate the optimum system for each of the four general cooling systems followed by a sensitivity study for each parameter. Comparison of energy and water consumption follows from the results of the performance model...

Waste heat management in the electric power industry : issues of energy conservation and station operation under environmental constraints

Adams, E. Eric; Harleman, Donald R. F.
Fonte: MIT Energy Laboratory Publicador: MIT Energy Laboratory
Tipo: Relatório Formato: 3133327 bytes; application/pdf
EN_US
Relevância na Pesquisa
66.1%
Over the past three years, the Energy Laboratory, in cooperation with the R.M. Parsons Laboratory for Water Resources and Hydrodynamics at M.I.T. has been under contract with DOE/ECT to study various water and waste heat management issues associated with the choice of cooling systems for large steam-electric power plants. The purpose of this report is to summarize the major findings to-date of this study. In addition, an introduction or background section proceeds the summary so that the results can be better integrated into the larger picture of water and waste heat management.; Over the past three years, the Energy Laboratory, in cooperation with the R.M. Parsons Laboratory for Water Resources and Hydrodynamics at M.I.T. has been under contract with DOE/ECT to study various water and waste heat management issues associated with the choice of cooling systems for large steam-electric power plants. The purpose of this report is to summarize the major findings to-date of this study. In addition, an introduction or background section proceeds the summary so that the results can be better integrated into the larger picture of water and waste heat management.

Greening the Wind : Environmental and Social Considerations for Wind Power Development

Ledec, George C.; Rapp, Kennan W.; Aiello, Roberto G.
Fonte: World Bank Publicador: World Bank
Relevância na Pesquisa
56.11%
This report identifies good practices for managing the key environmental and social issues associated with wind power development and provides advice on how best to address these issues in project planning, construction, and operation and maintenance. It provides detailed background information on wind power, with special focus on two emerging themes of growing scientific and public interest: namely the biodiversity-related impacts and the broader socioeconomic and cultural dimensions of wind power development. Like wind power itself, the scope of this report is worldwide although special attention is paid to the issues characteristic of the Latin America and Caribbean (LAC) region. While the principal focus is on land-based wind power, it also briefly addresses the environmental and social impacts related to off shore wind development. Wind power today is widely regarded as a key component of an environmentally sustainable, low-carbon energy future because it is renewable, requires almost no water, and generates near-zero emissions of greenhouse gases and other pollutants. In many parts of the world...

Power System Planning in India : Incorporating Environmental Externality Costs and Benefits

World Bank
Fonte: Washington, DC Publicador: Washington, DC
Relevância na Pesquisa
46.15%
This paper has been prepared in accordance with the terms of reference for a study on power system planning in India: incorporating externality costs and benefits. It reviews estimates of the external costs of power in international studies as well as in India and compares the figures available. It also comments on the validity of the external cost estimates available and the use made of them in power system planning and regulation both outside and inside India. The structure is as follows. Section two reviews the external cost estimates of electricity generation in the European Union (EU), and other countries. It also reports some recent work on the external costs associated with transmission. Some comments for the range of estimates are offered. Section three reviews a few studies on external costs for India and compares those with the international estimates. Section four discusses the use made of external cost data in power system planning and regulation both internationally and in India and makes some recommendations for possible reforms in the Indian case. Section five reviews the Indian and international estimates of external costs of hydro and section six does the same for resettlement and rehabilitation (RR) costs. Section seven offers some conclusions.

Technology Assessment of Clean Coal Technologies for China : Volume 2. Environmental and Energy Efficiency Improvements for Non-power Uses of Coal

World Bank
Fonte: Washington, DC Publicador: Washington, DC
EN_US
Relevância na Pesquisa
56.12%
Analysts expect China to continue improving the efficiency of energy production and use, thereby decoupling the traditional relationship between gross domestic product (GDP) and energy consumption. Environmentally acceptable economic growth is closely linked with further improvements in the overall efficiency of energy use. Both of these goals will require a continued increase in the use of coal to produce electricity, along with a more deliberate and rapid transition from direct coal combustion to the use of electricity and other cleaner coal-based fuel sources, especially for cooking, space heating, and industrial furnaces. The opportunity for environmental improvement in conjunction with economic growth lies in the wise adoption of clean coal technologies (CCT) for both the electric power and non-power sectors. This report presents CCT options for the power sector that can help China achieve these twin goals. The CCT options are: 1) air pollution controls for particulates, sulphur dioxide, and nitrous oxide; and 2) advanced electricity generation technologies--supercritical pulverized-coal boilers...

Syrian Arab Republic Electricity Sector Strategy Note

World Bank
Fonte: Washington, DC Publicador: Washington, DC
EN_US
Relevância na Pesquisa
46.22%
This electricity sector strategy note was prepared by the World Bank, at the request of the Government of Syria. It identifies options for the Government to improve the financial and technical performance of the electricity sector. The note focuses in particular on the following major sector objectives: a) increasing the efficiency of the electric power sector, including by reducing large technical and commercial losses now standing at 27 percent of demand; b) reducing the growing gap between demand and supply of electricity through capacity expansion, thus enhancing security of electricity supply and reducing power outages; c) increasing security of supply further in an environmentally sustainable manner by developing vigorous energy efficiency and renewable energy programs; d) encouraging regional energy integration through a series of targeted investments in electric power and natural gas; e) attracting private sector investment into generation capacity expansion, including in renewable energy, through independent power producers; and f) making the electricity sector financially viable and coordinating natural gas production plans with electricity generation requirements.

Mapping Smart-Grid Modernization in Power Distribution Systems

Oguah, Samuel; Chattopadhyay, Debabrata
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
46.17%
Smart grids are an essential element in improving efficiency that is relevant to utilities in all countries - from advanced utilities with robust grids to those whose grids barely keep up with demand. This note provides practical guidance for stakeholders in defining smart-grid goals, identifying priorities, and structuring investment plans. While most of these principles apply to any part of the electricity grid (transmission, distribution, off-grid), the note focuses on the distribution network. Modernizing the grid can help utilities address issues in service delivery such as reducing technical and commercial losses, promoting energy conservation, managing peak demand, improving reliability, integrating high levels of distributed generation (such as mini-grids and power sources with variable output), and accommodating the rising use of electric vehicles. To harness these benefits, it is essential that well-designed plans be developed for the implementation of smart-grid goals and objectives. Smart elements in a grid will differ greatly depending on the state of the power system and the country context. A smart-grid roadmap will therefore vary considerably across countries...

Best Practices for Market-Based Power Rationing : Implications for South Africa

World Bank
Fonte: Washington, DC Publicador: Washington, DC
Tipo: Economic & Sector Work :: Energy-Environment Review; Economic & Sector Work
ENGLISH; EN_US
Relevância na Pesquisa
56.32%
This report summarizes South Africa's energy challenges, efforts to establish a low-carbon energy strategy through the Power Conservation Program; and several World Bank backed initiatives to help the country save energy, reduce greenhouse gas emissions, and help South Africa cope with a power crunch. The Power Conservation Program has proved its effectiveness. The economic benefits of the program include the reduced need for dispatching expensive, oil-fired power plants. The national electric utility, Eskom, has maintained the Power Conservation Program as an option that can be expanded beyond the large industrial customer base, if further power shortages arise due to an imbalance between electricity supply and demand. The system is well understood among Eskom's staff, integrated into business processes, and it can be adjusted to accommodate a larger customer base, if necessary. It is an excellent hedging mechanism that can help Eskom to manage power system reliability if the reserve margins deteriorate in the future.

Mexico - Low-Carbon Development : Main Report; Mexico - Estudio sobre la disminución de emisiones de carbono

World Bank
Fonte: World Bank Publicador: World Bank
Tipo: Economic & Sector Work :: Other Environmental Study
ENGLISH
Relevância na Pesquisa
46.15%
This study analyzes a range of energy efficiency options available in Mexico, including supply-side efficiency improvements in the electric power and oil and gas industries and demand-side electricity efficiency measures to limit high-growth energy-consuming activities, such as air conditioning and refrigeration. It also evaluates a range of renewable energy options that make use of the country's vast wind, solar, biomass, hydro, and geothermal resources. But low-carbon (CO2) development is not only about energy production and consumption. In Mexico one of the most important sources of greenhouse gas emissions continues to be emissions from deforestation. The rate of deforestation has fallen steadily in Mexico over the past decades. Expanded programs for forest management, wildlife conservation, and efforts to increase the stock of forests can provide needed employment in rural areas and help make Mexican forests net absorbers of CO2 in the coming years. A fundamental question often asked about low-cost mitigation options is why they are not already being undertaken. As the study shows...

Practical Guidance for Defining a Smart Grid Modernization Strategy : The Case of Distribution

Madrigal, Marcelino; Uluski, Robert
Fonte: Washington, DC: World Bank Publicador: Washington, DC: World Bank
Tipo: Publications & Research :: Publication
ENGLISH; EN_US
Relevância na Pesquisa
46.17%
This report provides some practical guidance on how utilities can define their own smart grid vision, identify priorities, and structure investment plans. While most of these strategic aspects apply to any area of the electricity grid, the document focuses on the segment of distribution. The guidance includes key building blocks that are needed to modernize the distribution grid and provides examples of grid modernization projects. Potential benefits that can be achieved (in monetary terms) for a given investment range are also discussed. The concept of the smart grid is relevant to any grid regardless of its stage of development. What varies are the magnitude and type of the incremental steps toward modernization that will be required to achieve a specific smart grid vision. Importantly, a utility that is at a relatively low level of grid modernization may leap frog one or more levels of modernization to achieve some of the benefits offered by the highest levels of grid modernization. Smart grids impact electric distribution systems significantly and sometimes more than any other part of the electric power grid. In developing countries...

Transparency and Social Accountability in the Egyptian Power Sector

World Bank Group
Fonte: Washington, DC Publicador: Washington, DC
Tipo: Publications & Research :: ESMAP Paper; Publications & Research
ENGLISH; EN_US
Relevância na Pesquisa
46.12%
The World Bank's initiatives of social accountability and transparency over the past two decades are increasingly founded on the notion that transparency and social accountability of public institutions are essential for stimulating economic growth. Social accountability refers to the responsiveness of the state to the needs of its citizens, and encompasses a broad range of actions and mechanisms such as tracking of public expenditures, monitoring of public service delivery, and working with citizen advisory boards. Transparency entails access to and effective use of information by citizens, civil society organizations, non-governmental organizations (NGOs), local communities, and the private sector. To achieve this objective, the World Bank and Egypt Egyptian Electric Utility and Consumer Protection Regulatory Agency (ERA) - in consultation with Kantor management consultant - finds it necessary to establish systems and procedures for: (a) proactively disclosing information about the power sector's quality of service...

Computer optimization of dry and wet/dry cooling tower systems for large fossil and nuclear power plants

Choi, Michael; Glicksman, Leon R.
Fonte: MIT Energy Laboratory Publicador: MIT Energy Laboratory
Tipo: Relatório Formato: 11159992 bytes; application/pdf
EN_US
Relevância na Pesquisa
55.96%
There is a projected shortage of water supply for evaporative cooling in electric power industry by the end of this century, Thus, dry and wet/dry cooling tower systems are going to be the solution for this problem. This study has determined the cost of dry cooling compared to the conventional cooling methods. Also, the savings by using wet/dry instead of all-dry cooling has been determined. A total optimization has been performed for power plants with dry cooling tower systems using metal-finned-tube heat exchangers and surface condensers. The optimization minimizes the power production cost. The program does not use pre-designed heat exchanger modules. Rather, it optimizes the heat exchanger and its air and water flow rates. In the base case study, the-method of replacing lost capacity assumes the use of gas turbines. As a result of using dry cooling towers in an 800 MWe fossil plant, the incremental costs with the use of high back pressure turbine and conventional turbine over all-wet cooling are 11% and 15%, respectively. For a 1200 MWe nuclear plant, these are 22% and 25%, respectively. Since the method of making up lost capacity depends on the situation of a utility, considerable effort has been placed on testing the effects of using different methods of replacing lost capacity at high ambient temperatures by purchased energy. The results indicate that the optimization is very sensitive to the method of making up lost capacity. It is...

Novel low power CAM architecture

Ng, Ka Fai
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
55.89%
One special type of memory use for high speed address lookup in router or cache address lookup in a processor is Content Addressable Memory (CAM). CAM can also be used in pattern recognition applications where a unique pattern needs to be determined if a match is found. CAM has an additional comparison circuit in each memory bit compared to Static Random Access Memory. This comparison circuit provides CAM with an additional capability for searching the entire memory in one clock cycle. With its hardware parallel comparison architecture, it makes CAM an ideal candidate for any high speed data lookup or for address processing applications. Because of its high power demand nature, CAM is not often used in a mobile device. To take advantage of CAM on portable devices, it is necessary to reduce its power consumption. It is for this reason that much research has been conducted on investigating different methods and techniques for reducing the overall power. The objective is to incorporate and utilize circuit and power reduction techniques in a new architecture to further reduce CAM’s energy consumption. The new CAM architecture illustrates the reduction of both dynamic and static power dissipation at 65nm sub-micron environment. This thesis will present a novel CAM architecture...