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Geração de energia elétrica a partir da fonte eólica offshore.; Electricity generation from the offshore wind energy source.

Viterbo, Jean Carlo
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 15/05/2008 PT
Relevância na Pesquisa
66.46%
Nas últimas décadas, a fonte eolielétrica é a que sinaliza maior crescimento mundial dentre as demais. A curva de aprendizagem tecnológica do setor mostra queda do custo entre 15% a 20% a cada 3 anos. Países ativos no setor eólico se esforçam pela meta de 12% de participação na produção elétrica mundial em 2020. A contribuição da geração eolielétrica offshore é fundamental para essa meta, pela proximidade aos centros de carga, com ganhos de eficiência, de escala e reduzido impacto ambiental e visual. Apesar do crescimento do parque gerador nacional em 2006, há carência na produção no curto prazo. Contraditoriamente, há ventos abundantes para geração eolielétrica e o prévio arcabouço industrial que seria necessário para desenvolver o setor. Apesar do incentivo governamental (PROINFA), o setor eólico brasileiro ainda não decolou como esperado. O objetivo deste trabalho é reforçar o debate sobre a importância da diversificação da matriz, em prol da estratégia de segurança do suprimento energético nacional e da redução da emissão de gases de efeito estufa. Em rumo a esse objetivo, são colocados argumentos com abordagem ampla e com abordagem específica. Na abordagem ampla, esta pesquisa propõe uma maior inserção da fonte eólica na matriz elétrica nacional como uma das opções a serem consideradas de maneira mais relevante nas táticas de diversificação da matriz...

Offshore wind turbine simulation: multibody drive train. Back-to-back NPC (neutral point clamped) converters. fractional-order control

Melício, Rui; Seixas, Mafalda; Mendes, Victor
Fonte: Energy - Elsevier Publicador: Energy - Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
56.12%
This paper is on offshore wind energy conversion systems installed on the deep water and equipped with back-to-back neutral point clamped full-power converter, permanent magnet synchronous generator with an AC link. The model for the drive train is a five-mass model which incorporates the dynamic of the structure and the tower in order to emulate the effect of the moving surface. A three-level converter and a four-level converter are the two options with a fractional-order control strategy considered to equip the conversion system. Simulation studies are carried out to assess the quality of the energy injected into the electric grid. Finally, conclusions are presented.

Simulation of offshore wind system with two-level converters: HVDC power transmission

Melicio, Rui; Seixas, Mafalda; Mendes, Victor; Pousinho, Hugo
Fonte: 16th International Power Electronics and Motion Control Conference and Exposition Publicador: 16th International Power Electronics and Motion Control Conference and Exposition
Tipo: Aula
ENG
Relevância na Pesquisa
76.31%
A new integrated mathematical model for the simulation of offshore wind energy conversion system performance is presented in this paper. The mathematical model considers an offshore variable-speed turbine in deep water equipped with a permanent magnet synchronous generator using full-power two-level converter, converting the energy of a variable frequency source in injected energy into the electric network with constant frequency, through a high voltage DC transmission submarine cable. The mathematical model for the drive train is a concentrate two mass model which incorporates the dynamic for the structure and tower due to the need to emulate the effects of the moving surface. Controller strategy considered is a proportional integral one. Also, pulse width modulation using space vector modulation supplemented with sliding mode is used for trigger the transistor of the converter. Finally, a case study is presented to access the system performance.

Three-level Converter in Offshore Wind Energy Systems: New Strategy for Unbalancing in Capacitors Voltage

Seixas, Mafalda; Melicio, Rui; Mendes, Victor; Figueiredo, Joao
Fonte: ELSEVIER - Procedia Technology Publicador: ELSEVIER - Procedia Technology
Tipo: Parte de Livro
ENG
Relevância na Pesquisa
56.1%
This paper is on an offshore wind energy conversion system equipped with full-power three-level converter and permanent magnet synchronous generator. Multi-level converters, namely three-level converters, are limited by unbalance voltage in the direct current link capacitors. A new control strategy for the selection of the output voltage vectors is proposed in order to improve balance of voltage in the capacitors.

Simulation of Offshore Wind System with Three-Level Converters: HVDC Power Transmission in Cloud Scope

Seixas, M.; Melício, R.; Mendes, V.M.F.; Collares-Pereira, M.; Dos Santos, M. P.
Fonte: IFIP International Federation for Information Processing Publicador: IFIP International Federation for Information Processing
Tipo: Parte de Livro
ENG
Relevância na Pesquisa
76.23%
This paper is on a simulation for offshore wind systems in deep water under cloud scope. The system is equipped with a permanent magnet synchronous generator and a full-power three-level converter, converting the electric energy at variable frequency in one at constant frequency. The control strategies for the three-level are based on proportional integral controllers. The electric energy is injected through a HVDC transmission submarine cable into the grid. The drive train is modeled by a three-mass model taking into account the resistant stiffness torque, structure and tower in the deep water due to the moving surface elevation. Conclusions are taken on the influence of the moving surface on the energy conversion.

Impact of weather conditions on the windows of opportunity for operation of offshore wind farms in portugal 

Silva, N.; Estanqueiro, Ana
Fonte: Multi-Science Publishing Publicador: Multi-Science Publishing
Tipo: Artigo de Revista Científica
Publicado em //2013 ENG
Relevância na Pesquisa
66.41%
The deployment of offshore wind parks face several challenges. Among them are the difficulties introduced by the atmospheric and sea conditions in accessing those wind parks. A window of opportunity is a timeframe when weather and sea conditions are acceptable and enable to perform specific tasks in the installation and operation/maintenance of the offshore wind park. This study identifies typical time periods of windows of opportunity to access three offshore Portuguese maritime regions. The accessibility conditions also take into account the system type transportation method for local access, namely, rubber boat, boat with OAS or helicopter. It was concluded that Portugal has adequate conditions for offshore site maintenance strategies, with a large number of windows of opportunity, but they are relatively short, therefore the installation of offshore wind parks must be carefully planned. This is an important factor in favor of the offshore wind farm deployments on the country.

Wind resource assessment method for floating deep offshore wind turbines

Estanqueiro, Ana; Couto, A.; Rodrigues, L.; Marujo, R.
Fonte: Institution of Engineering and Technology - IET Publicador: Institution of Engineering and Technology - IET
Tipo: Artigo de Revista Científica
Publicado em //2014 ENG
Relevância na Pesquisa
56.35%
This study presents a new methodology for the assessment of the wind energy resource at deep offshore locations where the use of floating wind turbines is foreseen. The wind resource assessment methodology developed follows the principles used by IEC 61400-12-1 standard in general and proposes the use of experimental data from a floating light detection and ranging (LIDAR) system on a deep offshore region – that assumes the role of the ‘temporary mast’ – and a coastal meteorological mast installed onshore acting as the ‘permanent met mast’. The methodology takes into consideration the time shift between the locations of the two measurement points and the wind direction associated with different atmospheric phenomena. The results obtained conclude that the methodology increases the accuracy of the wind resource assessment campaign while reducing the involved costs and technical risks. An added advantage is the possibility of extending this methodology for the evaluation of the power performance of floating wind turbines during the operational phase of the power plant.

Optimal Integration of Offshore Wind Power for a Steadier, Environmentally Friendlier, Supply of Electricity in China

Lu, Xi; McElroy, Michael Brendon; Nielsen, Chris; Chen, Xinyu; Huang, Junling
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
56.24%
Demand for electricity in China is concentrated to a significant extent in its coastal provinces. Opportunities for production of electricity by on-shore wind facilities are greatest however in the north and west of the country. Using high resolution wind data derived from the GEOS-5 assimilation, this study shows that investments in off-shore wind facilities in these spatially separated regions (Bohai-Bay or BHB, Yangtze-River Delta or YRD, Pearl-River Delta or PRD) could make an important contribution to overall regional demand for electricity in coastal China. An optimization analysis indicates that hour-to-hour variability of outputs from a combined system can be minimized by investing 24% of the power capacity in BHB, 30% in YRD and 47% in PRD. The analysis suggests that about 28% of the overall off-shore wind potential could be deployed as base load power replacing coal-fired system with benefits not only in terms of reductions in CO2 emissions but also in terms of improvements in regional air quality. The interconnection of off-shore wind resources contemplated here could be facilitated by China’s 12th-five-year plan to strengthen inter-connections between regional electric-power grids.; Engineering and Applied Sciences

Teoria de carteiras e a alocação de parques eólicos offshore

Silva, Lana Viviane Linhares da Costa
Fonte: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Administração; Políticas e Gestão Públicas; Gestão Organizacional Publicador: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Administração; Políticas e Gestão Públicas; Gestão Organizacional
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
46.49%
The consumption of energy on the planet is currently based on fossil fuels. They are responsible for adverse effects on the environment. Renewables propose solutions for this scenario, but must face issues related to the capacity of the power supply. Wind energy offshore emerging as a promising alternative. The speed and stability are greater winds over oceans, but the variability of these may cause inconvenience to the generation of electric power fluctuations. To reduce this, a combination of wind farms geographically distributed was proposed. The greater the distance between them, the lower the correlation between the wind velocity, increasing the likelihood that together achieve more stable power system with less fluctuations in power generation. The efficient use of production capacity of the wind park however, depends on their distribution in marine environments. The objective of this research was to analyze the optimal allocation of wind farms offshore on the east coast of the U.S. by Modern Portfolio Theory. The Modern Portfolio Theory was used so that the process of building portfolios of wind energy offshore contemplate the particularity of intermittency of wind, through calculations of return and risk of the production of wind farms. The research was conducted with 25.934 observations of energy produced by wind farms 11 hypothetical offshore...

Regulating Future Offshore Grids: Economic impact analysis on wind parks and transmission system operators

KITZING, Lena; SCHRÖDER, Sascha T.
Fonte: Instituto Universitário Europeu Publicador: Instituto Universitário Europeu
Tipo: Trabalho em Andamento Formato: application/pdf; digital
EN
Relevância na Pesquisa
56.51%
The increasing development of offshore wind parks in the European offshore territory may lead to meshed offshore grids in which each wind park might be connected to several countries. Such offshore grids could be subject to various regulatory regimes, depending on the degree of cooperation between the respective countries. This study focuses on how investors in wind parks and transmission systems are affected by the choice of regulatory regime in offshore grids with one to four countries connected. In order to capture the uncertainties related to the exposure to market prices as well as risks related to line failures, we develop a stochastic model for an exemplary wind park and offshore grid. This yields the real option values of operational flexibility from additional connections. Simulation results show that the choice of regulatory regime, including market access and pricing rules, can have a significant impact on the value of a wind park and on the value of the interconnection capacity in the offshore grid. The impact can both be positive and negative, implying a complex incentive structure for the involved actors. If contrary effects are not reflected in the remuneration level of a wind park, for example in the price premium level...

Conversão eólica offshore ligada à rede elétrica: modelação e simulação

Seixas, Mafalda Maria Morais
Fonte: Universidade de Évora Publicador: Universidade de Évora
Tipo: Tese de Doutorado
POR
Relevância na Pesquisa
56.44%
A tese incide sobre a modelação e simulação de um sistema de conversão de energia eólica offshore com ligação à rede elétrica por transmissão de energia elétrica estudada quer em corrente alternada quer em corrente contínua, no contexto atual de reestruturação do setor elétrico, e integrando a dinâmica relevante. Além da transmissão de energia elétrica, o sistema é constituído por uma plataforma flutuante semissubmersível; uma turbina eólica de velocidade variável; um sistema de transmissão de energia mecânica cuja dinâmica é descrita respetivamente por uma, duas, três ou cinco massas girantes; um gerador síncrono com excitação assegurada por meio de ímanes permanentes; um conversor eletrónico de energia, descrito respetivamente por um conversor de dois níveis ou por um conversor multinível na configuração de díodos de ligação múltipla de três, de quatro, de cinco ou de p níveis. O controlo do sistema utiliza o modo de deslizamento associado com a modulação PWM por vetores espaciais e controladores PI, ditos de clássicos, ou controladores PI de ordem fracionária. Os comportamentos que advêm do facto da energia eólica ser uma fonte de energia variável, com intermitência, assim como...

Estudio de las solicitaciones meteoceánicas extremas y las respuestas asociadas a una plataforma eólica flotante tipo Spa; Study of the extreme marine loads and the associated response of an offshore spar-type floating platform

Rodríguez Marijuán, Alberto
Fonte: Universidade de Cantabria Publicador: Universidade de Cantabria
Tipo: Trabalho de Conclusão de Curso
SPA
Relevância na Pesquisa
56.4%
RESUMEN: El objetivo del presente estudio es determinar, utilizando herramientas básicas de cálculo, las solicitaciones que generan los diferentes fenómenos climáticos de la dinámica marina –viento, corrientes y oleaje– sobre una plataforma flotante tipo SPAR para eólica offshore. A partir de ellas, pueden hallarse las respuestas de la misma, considerando los diferentes elementos que juegan un papel fundamental en el proceso, como son el sistema de amarre y las amortiguaciones hidrodinámicas. Como introducción y punto de partida, se hace un recorrido por la situación actual de los muchos elementos relacionados con la explotación de energía eólica offshore, como son las características y tendencias de la energía eólica, las características especiales del ambiente marino, las diferentes plataformas que existen y se están desarrollando –fijas y flotantes–, los tipos de sistemas de amarre y una pequeña reseña de las clases de anclajes que se suelen utilizar. Los apartados de cálculo se han realizado principalmente siguiendo las pautas e indicaciones de manuales como el de Subrata Chakrabarty (Handbook of Offshore Engineering, 2005) y estándares para diseño de estructuras offshore como los DNV Standards. Se ha utilizado la expresión de Morison para determinar las cargas horizontales –estacionarias y no estacionarias– sobre el cuerpo de la plataforma debidas a viento...

Implementing Onshore Wind Power Projects

Elizondo Azuela, Gabriela; Ben, Rafael
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Journal Article; Publications & Research :: Brief
EN_US
Relevância na Pesquisa
56.39%
The kinetic energy in wind is converted into mechanical power in specialized propeller-driven turbines mounted on towers. A generator inside the turbine converts the mechanical power into electricity. Utility-scale wind turbines range in size from 100 kilowatts to as large as several megawatts. Turbines can be built on land or offshore and are grouped into 'wind farms' that provide bulk power to the electrical grid. Smaller turbines are used for homes, telecommunications dishes, and water pumping, sometimes in connection with diesel generators, batteries, and photovoltaic systems. Such hybrid wind systems are typically used in remote, off-grid locations, where a connection to the utility grid is not available. This note focuses on onshore wind energy, which is more widely established and has lower risks than offshore wind.

China - Meeting the Challenges of Offshore and Large-Scale Wind Power : Regulatory Review of Offshore Wind in Five European Countries

World Bank
Fonte: World Bank Publicador: World Bank
Tipo: Economic & Sector Work :: Energy Study
ENGLISH
Relevância na Pesquisa
66.52%
The objective of this study is to review international experience in offshore wind power development and draw on the lessons learned from the experience of different countries. To date, that experience has predominantly been limited to Europe. Significantly different regulatory and physical planning approaches have been taken in the different countries. Hence, the experience is particularly helpful in providing suggestions for a new market. The study focuses on describing the past, present, and planned future regulatory regime in each country. Both positive and negative experiences to date have been explored in the context of regulatory arrangements, and they have been used to draw general conclusions on the characteristics of the most effective systems. At the same time, it has been recognized throughout that a single model is unlikely to provide the 'best fit' for all countries, given national differences. Chapters two, three, and four, focusing on market development, targets and incentives, and regulatory framework...

China - Meeting the Challenges of Offshore and Large-Scale Wind Power : Strategic Guidance

World Bank
Fonte: World Bank Publicador: World Bank
Tipo: Economic & Sector Work :: Energy Study
ENGLISH
Relevância na Pesquisa
46.59%
In view of the escalating global problems associated with the environment, energy, and natural resources, especially the increasing sign of global climate change, wind power is receiving more and more high-level attention on a global scale, and it has reached a rapid rate of development as a result of the combined efforts of various countries. The world's installed capacity of wind power has already surpassed 100 GW, and wind power has become an essential part of the world's energy structure. This publication comprises three main parts: i) part A contains the key messages emerging from the research and analytical work undertaken by Garrad Hassan and Partners Limited, the team of Chinese experts led by the national energy administration, and staff and consultants of the World Bank; ii) part B comprises the Garrad Hassan and Partners Limited study, 'implementation guidance for offshore and large-scale onshore wind power development in China,' and its annexes; and iii) part C focuses on the workshop on offshore and intertidal wind power development in China...

Simulation of rectifier voltage malfunction on OWECS, four-level converter, HVDC light link: Smart grid context tool

Melicio, Rui
Fonte: Energy Conversion and Management-Elsevier Publicador: Energy Conversion and Management-Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.33%
This paper presents a model for the simulation of an offshore wind system having a rectifier input voltage malfunction at one phase. The offshore wind system model comprises a variable-speed wind turbine supported on a floating platform, equipped with a permanent magnet synchronous generator using full-power four-level neutral point clamped converter. The link from the offshore floating platform to the onshore electrical grid is done through a light high voltage direct current submarine cable. The drive train is modeled by a three-mass model. Considerations about the smart grid context are offered for the use of the model in such a context. The rectifier voltage malfunction domino effect is presented as a case study to show capabilities of the model.

Cyclic behaviour of monopile foundations for offshore wind turbines in clay

Lau, Ben Hong
Fonte: University of Cambridge; Department of Engineering; Churchill College Publicador: University of Cambridge; Department of Engineering; Churchill College
Tipo: Thesis; doctoral; PhD
EN
Relevância na Pesquisa
66.28%
Investment into offshore wind farms has been growing to address the growing threat of climate change. The majority of offshore wind turbines (both current and planned) are founded on monopiles, large circular steel pipe piles ranging from 4.0 m ? 7.5 m in diameter. Based on available borehole records, most planned wind turbines in the UK will be founded in overconsolidated clay deposits. Monopile design is done via usage of the well established p-y curves. However, there are issues with the usage of the p-y curves. Firstly, the curves may be unsuitable to model the monopile?s behaviour as it is expected to behave similarly to a rigid pile rather than flexibly. Secondly, the curves may not accurately estimate the initial pile-soil stiffness. Thirdly, the curves are not comprehensive enough to account for the accumulated strain and stiffness changes resulting from cyclic loading. Considering these issues, research was carried out to improve the current design of monopiles in clay by carrying out displacement controlled monotonic and load controlled cyclic load tests in a centrifuge. Results from monotonic tests suggest that the DNV (2014) design methodology to construct p-y curves in clay based on Matlock?s (1970) soft clay criterion significantly underestimate stiffness. Findings suggested that the experimental p-y curves could be characterised through modification of the criterion. Modification of the criterion produced estimates that matched the 3.83 m monopile experimental curves. Pile toe shear force was observed to contribute little to ultimate lateral resistance and stiffness. Despite the marginal contribution...

NEMS Modeling of East Coast Offshore Wind: Examining the Assumptions

Morris, Cullen
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Masters' project
Publicado em 10/12/2010 EN_US
Relevância na Pesquisa
66.46%
The Energy Information Administration’s (EIA) National Energy Modeling System (NEMS) is widely considered a credible source for domestic energy projections, and is frequently used to inform state and federal policy decisions. The model is used to publish the Annual Energy Outlook (AEO). The 2010 AEO publication suggest that offshore wind development along the eastern seaboard is predicted to grow very little over the next 25 years, yet there are currently over 2.5 GW of proposed offshore projects in this area, with interest growing steadily. This project seeks to determine whether NEMS modeling of offshore wind is based on accurate assumptions and on the current state of the industry. Key factors that shape NEMS results are examined. These factors include the shallow water offshore wind resource off the eastern seaboard, the overnight capital costs assumed by the model, and the way in which transmission and reliability costs associated with offshore wind are treated. The assumptions used by the EIA in their modeling were examined for each of these factors. Modeling scenarios were built to test the sensitivity of the results to changes in these assumptions. This method helped to identify which parameters weigh most heavily in how the model determines whether offshore wind will play a role in the near-term future of renewable energy production. Findings indicate that wind resource estimates are out-dated...

Simulation of a rectifier malfunction on an offshore wind system with HVDC transmission

Melicio, Rui
Fonte: IEEE International Conference on Industrial Technology — ICIT 2015 Publicador: IEEE International Conference on Industrial Technology — ICIT 2015
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
96.33%
A new integrated mathematical model for the simulation of an offshore wind system having a rectifier input voltage malfunction at one phase is presented in this paper. The mathematical model considers an offshore variable-speed wind turbine on a floating platform, equipped with a permanent magnet synchronous generator using full-power three-level converter to inject energy into the electric network, through a high voltage direct current transmission submarine cable. The model for the drive train is a discrete three mass, incorporating the dynamic of the moving surface. A case study is presented to access conclusion about the malfunction.

Simulation of a rectifier malfunction on a offshore wind system with HVDC transmission

Seixas, Mafalda; Melício, R.; Mendes, V. M. F.; Couto, Carlos
Fonte: IEEE Publicador: IEEE
Tipo: Conferência ou Objeto de Conferência
Publicado em 19/03/2015 ENG
Relevância na Pesquisa
86.33%
A new integrated mathematical model for the simulation of an offshore wind system having a rectifier input voltage malfunction at one phase is presented in this paper. The mathematical model considers an offshore variable-speed wind turbine on a floating platform, equipped with a permanent magnet synchronous generator using full-power three-level converter to inject energy into the electric network, through a high voltage direct current transmission submarine cable. The model for the drive train is a discrete three mass, incorporating the dynamic of the moving surface. A case study is presented to access conclusion about the malfunction.; Fundação Ciência e Tecnologia, through IDMEC/LAETA, Instituto Superior Técnico, Universidade de Lisboa