Η παρούσα διπλωματική εργασία πραγματεύεται τη μελέτη και κατασκευή εργαστηριακής διάταξης για προσομοίωση συστήματος μετατροπής αιολικής ενέργειας σε ηλεκτρική με ασύγχρονη γεννήτρια δακτυλιοφόρου δρομέα και ηλεκτρονικούς μετατροπείς ισχύος. Η εργασία αυτή εκπονήθηκε στο Εργαστήριο Ηλεκτρομηχανικής Μετατροπής Ενέργειας του Τμήματος Ηλεκτρολόγων Μηχανικών και Τεχνολογίας Υπολογιστών της Πολυτεχνικής Σχολής του Πανεπιστημίου Πατρών. Σκοπός της εργασίας είναι η μελέτη και η κατασκευή διάταξης με χρήση ασύγχρονης μηχανής δακτυλιοφόρου δρομέα και ενός τριφασικού αντιστροφέα πηγής τάσης, για να λειτουργήσει η μηχανή σαν γεννήτρια σε υποσύγχρονες ταχύτητες. Πρόκειται για ένα σύστημα που συναντάται στις ανεμογεννήτριες και προσφέρει πολλά πλεονεκτήματα και ευελιξία σε σχέση με της άλλες τοπολογίες. Αρχικά έγινε μια εκτενής μελέτη της λειτουργικής συμπεριφορά της διάταξης καθώς και τα πλεονεκτήματα και μειονεκτήματα που παρουσιάζει. Το πλήρες σύστημα της ανεμογεννήτριας περιλαμβάνει την ασύγχρονη γεννήτρια δακτυλιοφόρου δρομέα με το τύλιγμα του στάτη της συνδεδεμένο στο δίκτυο και το τύλιγμα του δρομέα συνδεδεμένο με έναν μετατροπέα AC-DC-AC συχνότητας με ηλεκτρονικά ισχύος. Ο μετατροπέας AC-DC-AC αποτελείται από δύο επιμέρους ελεγχόμενους μετατροπείς, το μετατροπέα από την πλευρά του δικτύου και τον μετατροπέα από την πλευρά του δρομέα, και έναν πυκνωτή στη συνεχή διασύνδεση των δύο μετατροπέων. Ακόμα γίνεται καταγραφή και ανάλυση των μεθόδων ελέγχου κλειστού βρόχου, οι οποίες αποτελούν μεγάλο κομμάτι για την ομαλή λειτουργία του συστήματος. Έπειτα ακολούθησε η προσομοίωση του συστήματος με χρήση του λογισμικού MATLAB/Simulink. Τα αποτελέσματα της προσομοιώσης παρουσιάζουν τη λειτουργία της ασύγχρονης μηχανής σαν γεννήτρια και ειδικότερα σαν ανεμογεννήτρια. Τόσο στην προσομοίωση όσο και στα πειράματα έγινε έλεγχος ανοιχτού βρόχου αν και η κατασκευή των πλακετών έγινε με προσανατολισμό να καθιστά εφικτό μελλοντικά την υλοποίηση ελέγχου κλειστού βρόχου. Τέλος ακολουθούν οι μετρήσεις, που καταγράφηκαν, από το εργαστηριακό πείραμα και τα συμπεράσματα για την λειτουργία της κατασκευής, καθώς επίσης και τρόποι βελτίωσης της. / This thesis is focused on the design and construction of laboratory layout to simulate the conversion of wind energy into electricity with wound rotor asynchronous generator and power electronic converters. This work was conducted in the Laboratory of Electromechanical Energy Conversion, Department of Electrical and Computer Engineering, Faculty of Engineering, University of Patras. The main purpose of this project was to study and build a system using a wound rotor asynchronous generator and a three-phase voltage source inverter to operate the machine as a generator in subsynchronous speeds. This system is commonly used in wind turbines and offers many advantages and flexibility compared to the other topologies. Initially, an extensive study has been made on the system operation, the advantages and disadvantages. The overall wind turbine system includes the wound rotor asynchronous generator with the stator winding connected directly to the grid and the rotor winding connected to a back-to-back frequency converter with power electronics. The back-to-back converter consists of two controlled converters, the grid side converter (GSC) and the rotor side converter (RSC) and a DC-link capacitor. Furthermore, it has been made a detail analysis of the converter’s closed loop control methods. Moreover, simulation of the system has been made using the software program MATLAB/Simulink. The results of the simulations clearly show the asynchronous machine in generation mode and operate as if in wind turbines. An open loop control was applied in both the simulation and the laboratory application. The manufacturing of the hardware is oriented to make possible the implementation of closed loop control in the future. Finally follow the measurements recorded by the laboratory experiment and the conclusion for the operation of the system in the laboratory, as well as ways to improve it.

Vindkraftverk ansluts idag i snabb takt till elnät runt om i världen. Elnäten är ofta inte tillräckligt dimensionerade på platser där vindkraftutbyggnad är lämplig vilket leder till ett behov av nätförstärkning. Förstärkning sker konventionellt genom att övergå till en högre spänning, något som kan vara förenat med stora kostnader och ledtider. Bland annat därför har en filosofi med beteckningen smarta elnät uppstått, som handlar om hur elnätsystemet ska se ut när det är mer anpassat till de nya energikällornas karaktär och samtidigt medför ett mer effektivt totalutnyttjande. För vindkraftverk kan det då handla om att i högre grad än idag reglera produktionen och understödja nätet, t.ex. via intelligenta kontrollsystem, kraftelektronik och energilager. I den här rapporten undersöks hur mycket vindkraft som kan anslutas till ett svagt elnät då principer för smarta elnät tillämpas och för att se om kostnaden blir lägre än anslutning via konventionella nätförstärkningsmetoder. Det svaga elnätet som studien bygger på ligger i Tidaholm. Vindkraftseffekten som ska anslutas är på 62 MW. Begränsningar i befintliga regionnätets ledningar gör att 60,3 MW kan anslutas med principer för smarta elnät, fast det finns flera skäl till att anta att den fulla mängden vindkraft går att ansluta. Detta till en kostnad som väsentligt understiger kostnaden att förstärka nätet på konventionellt sätt, kostnadsbesparingen uppgår till ca 58 % eller ca 95 Mkr.

The Scottish government’s aim of deriving 100 per cent of the nation’s electricity from renewable sources is dependent on the utilisation of wind energy. Social barriers, however, have continued to threaten these targets. Community benefit funds have often been paraded as the most common way of improving public attitudes towards wind farms in the United Kingdom, although little empirical evidence exists to support this notion. Using the proposed Ourack wind farm, approximately three and a half miles north of Grantown-on-Spey in the Scottish Highlands, this case study, consisting of a sequential explanatory research design comprised of an initial close-ended survey followed by in-depth semi-structured interviews, sought to explore the community’s perceptions of community benefits, identify the type of fund that the community wanted, and investigate the role of such benefit provisions in altering perceptions of wind farms. The key findings indicated that the majority of participants were in favour of benefits being provided, they preferred funding to be directed towards community organisations, and approximately one third of research participants (31.6 per cent) perceived the proposed wind farm in a more positive light after considering the possible benefits the region would accrue. Furthermore, the research indicated the need for community benefits to become a standardised part of the planning process, thus reducing the likelihood of financial benefits being perceived as bribes, and allowing developers to provide greater information about any proposed benefits scheme prior to applying for planning permission. There are implications of this study for academics researching the role of community benefits in wind farm planning, and policymakers and developers for understanding the wants and needs of community members.

Rapid deployment of terrestrial wind power plants (WPPs) is a function of accurate identification of areas suitable for WPPs. Efficient WPP site prospecting not only decreases installation lead time, but also reduces site selection expenses and provides faster reductions of greenhouse gas emissions. Combining conventional predictor variables, such as wind strength and proximity to transmission lines, with nonconventional socioeconomic and demographic predictor variables, will result in improved identification of suitable counties for WPPs and therefore accelerate the site prospecting phase of wind power plant deployment. Existing and under-construction American terrestrial WPPs located in the top 12 windiest states (230 as of June 2009) plus 178 potential county level predictor variables are introduced to logistic regression with stepwise selection and a random sampling validation methodology to identify influential predictor variables. In addition to the wind resource and proximity to electricity transmission lines, existence of a Renewable Portfolio Standard, the population density within a 200 mile radius of the county center, median home values, and farm land area in the county are the four strongest nonconventional predictors (Hosmer and Lemeshow Chi-Square = 9.1250, N = 1009, df = 8, p = 0.3319, - 2LogLikelihood = 619.521). Evaluation of the final model using multiple statistics, including the Heidke skill score (0.2647), confirms overall model predictive skill. The model identifies the existence of 238 suitable counties in the twelve state region that do not possess WPPs (~73% validated overall accuracy) and eliminates 654 counties that are not classified as suitable for WPPs. The 238 counties identified by the model represent ideal counties for further exploration of WPP development and possible transmission line construction. The results of this study will therefore allow faster integration of renewable energy sources and limit climate change impacts from increasing atmospheric greenhouse gas concentrations.

Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-08-13T14:24:33Z No. of bitstreams: 1 EVERSON BATISTA MARIANO - TESE (PPGMet) 2017.pdf: 4579830 bytes, checksum: 897e568e511f245cb9c7c10ef86f9866 (MD5) / Made available in DSpace on 2018-08-13T14:24:33Z (GMT). No. of bitstreams: 1 EVERSON BATISTA MARIANO - TESE (PPGMet) 2017.pdf: 4579830 bytes, checksum: 897e568e511f245cb9c7c10ef86f9866 (MD5) Previous issue date: 2017-05-26 / Capes / Na realização deste trabalho, foram analisadas variações espaciais e temporais do vento e da potência eólica para a região do nordeste setentrional oriental do Brasil. Para tanto, utilizou-se o modelo Brazilian developments on the Regional Atmospheric Modeling System (BRAMS) usando como entrada dados de reanálises do National Centers for Environmental Prediction (NCEP). Foram utilizados dados observados da velocidade do vento de três mesorregiões da Paraíba do período de 1 a 31 de outubro de 2010 para validação do modelo BRAMS. Reanálises do ERA-Interim, com resolução espacial de 0,75° x 0,75° foram utilizadas como uma segunda fonte de dados para o mesmo propósito. Nesta comparação, foram feitas correlações e aplicados testes de significância estatística, assim como, avaliação dos parâmetros de forma e escala da distribuição de Weibull. Após validação, foram geradas simulações do vento dos meses de março, junho, setembro e dezembro para o período de 1983 a 2013. Foram avaliadas as variações sazonais e interanuais da velocidade do vento em quatro cidades com parques eólicos instalados. Os resultados apontam coeficientes de correlações acima de 0,70 com significância estatística de 99% (α = 0,01). Na distribuição de Weibull, os parâmetros de forma e de escala mostraram-se próximos aos obtidos para os dados observados. Na variação sazonal, o mês de setembro apresentou velocidades do vento mais intensas e menos intensas em março, com valores intermediários verificados em junho e dezembro. Na distribuição espacial da média climatológica da velocidade do vento e da potência eólica, destacam-se influências da topografia, com velocidades mais intensa e maior potencial eólico sobre áreas mais elevadas. Variações interanuais, devido alterações na TSM dos oceanos Pacífico e Atlântico Tropicais, mostraram que em anos de El Niño e Gradiente Meridional Positivo o vento sobre o nordeste setentrional oriental do Brasil é intensificado e que a atuação simultânea de ambos, potencializa esse aumento. Com os resultados obtidos o uso da simulação de Densidade de Potencia Eólico (DPE), utilizando o modelo BRAMS pode ser aplicado em qualquer região da América do Sul. / In this work, wind and wind power spatial and temporal variability were analyzed for the northern region. For this, the Brazilian development on the Regional Atmospheric Modeling System (BRAMS) atmospheric model was used, alongside National Center for Environmental Prediction (NCEP) reanalysis data. Observed wind speed data from three meso regions of Paraíba from October 1 to October 31, 2010 were used to validate the BRAMS model. Reanalyses of the ERA-Interim with spatial resolution of 0.75 ° x 0.75 ° were used as a second data source for the same purpose. In this comparison, we performed correlation analysis and verified its statistical significance, as well as the evaluation of the shape and fit parameters of the Weibull distribution. After further validation, wind simulations were generated in the months of March, June, September and December for the period from 1983 to 2013. Seasonal and interannual wind speed variation was evaluated in four cities with wind farms. The results show correlation coefficients above 0.70 with a statistical significance of 99% (α = 0.01). In the Weibull distribution, the shape and fit parameters were close to those obtained for the observed data. In the wind speed seasonal variation, September presented more intense, while March showed lower wind speeds with intermediate values verified in June and december. Spatial distribution of the average climatological wind speed and wind power topography influences are highlighted, with higher velocities and greater wind potential on higher altitude areas. Interannual variations, due to changes in the SST of the Pacific and Atlantic Tropical Oceans, have shown that in the years influenced by El Niño and positive Southern Gradient, the wind over the north east to Brazil is intensified and that the simultaneous action of both SST gradients amplifies this increase. With the results obtained the use of the Wind Power Density (WPD) simulation using the BRAMS model can be applied in any region of South America.

Esta dissertação tratará do tema da geração de energia elétrica no Brasil e a análise financeira de projetos. Mais especificamente será abordada a energia eólica a qual é o aproveitamento dos ventos para a geração de energia. Nos últimos 10 anos, a capacidade instalada mundial de energia eólica cresceu em média 28% ao ano sendo que na Europa 3% da energia consumida já tem origem nos ventos. No Brasil, esse tipo de aproveitamento atinge apenas 0,3% de participação no fornecimento de energia elétrica do país apesar de excelentes condições naturais. Como objetivo geral, este estudo analisará a viabilidade financeira de um projeto de energia eólica no Estado brasileiro do Ceará. A metodologia utilizada será o estudo de caso, uma empresa geradora de energia eólica, sendo avaliada, financeiramente, pela teoria das opções reais. A TOR surge como alternativa aos métodos tradicionais de análise de investimentos e tenta superar as suas limitações incluindo a questão da incerteza. Os resultados obtidos comprovam a importância, tanto da energia eólica para a matriz energética brasileira, quanto da TOR como forma de precificar oportunidades / riscos embutidos em projetos. / This thesis will broach the generation of electricity in Brazil using wind power and project valuation analysis. During the last 10 years, the worldwide wind power installed capacity grew 28% on average per year and in Europe 3% of the energy consumption comes from this source of energy. In Brazil, this type of energy reaches only 0.3% of national energy supply besides the fact that the Country has excellent natural resources for this type of generation. The objective of this study is to make the valuation analysis of a wind energy project in the Brazilian State of Ceará. The research methodology used in this thesis will be the case study of a wind energy generation plant using the real option analysis. The ROA comes as an alternative method for the traditional valuation analysis and tries to overcome its limitations adding uncertainty. The result of this study confirms the importance not only of wind power to the Brazilian energy matrix but also the ROA as an alternative method to calculate risks and opportunities included in projects.

Os sistemas de controle e supervisão têm se revelado expressivamente importantes nos sistemas de produção. Garantir o funcionamento com qualidade dos processos industriais exige um controle permanente, sendo necessário manter constantes algumas variáveis. Um dos fatores que se destacam na utilização de monitoramento remoto é a possibilidade de centralizar o controle de um determinado processo em locais distintos, muitas vezes distantes do ponto de origem do problema, podendo ser acessado pelo responsável pelo processo e/ou muitas vezes resolvido pelo mesmo, sem a necessidade de locomover-se até o local do problema. Esse trabalho visou estudar e desenvolver um sistema utilizando a tecnologia de comunicação via rede elétrica e aquisição de dados, aplicado ao monitoramento e supervisão de temperatura do rotor de um aerogerador de pequeno porte por meio de um protótipo de simulação. O mesmo deu-se por meio de pesquisas e estudo de caso realizado em Laboratórios da Faculdade SATC, com a criação de um modelo de interface e aquisição de dados utilizando a rede elétrica para a transmissão e recepção de dados por intermédio da tecnologia PLC, como solução para o monitoramento remoto de uma variável definida como temperatura, simulando a temperatura do motor em um aerogerador de pequeno porte. Após a execução do protótipo, foram realizados testes comparativos entre a tecnologia PLC e a rede LAN em dois ambientes distintos: residencial e industrial. A análise do comportamento da rede LAN foi realizada através de um software de análise de redes, onde foram estabelecidos alguns parâmetros que representassem o desempenho da rede ao enviar e receber dados do sistema de monitoramento. Os resultados obtidos evidenciam as performances das tecnologias utilizadas como meios de transmissão, assim como apresentam um paralelo entre as mesmas. Os dados obtidos por este estudo mostram resultados satisfatórios da tecnologia PLC em relação à rede LAN, confirmando a possibilidade do uso desta tecnologia em sistemas de monitoramento remoto, permitindo assim um aumento na confiabilidade e comodidade operacional. / The control system and supervision have been revealed very important in product systems. To guarantee the function with quality, industrial process requires a permanent control being necessary keeping stable some variables. One important factor to point using remote monitoring is the possibility to centralize the control of one process in distinct place, many times far away from the problem original point. It can be accessed by responsible person for the process or many times solved by him without the necessity to be present where the problem started. This research studied and developed a monitoring system and supervision, using communication technology via electrical grid and data acquisition system. It was done by means of research and studies cases at SATC laboratory with data acquisition interface creation, using electric power distribution to transmit and receive the data by PLC technology as a solution to remote monitoring of a definite variable as temperature, simulating the temperature of a small wind power motor. After the prototype execution, comparatives tests were done between PLC technology and LAN network in two different environments: residential and industrial. The network behavior analysis was performed using a network analysis software, where were established some parameters that represent the performance of the network to send and receive data from the monitoring system.The data acquired in this research shows satisfactory results using PLC technology in relation to LAN network, confirming the possibility of use this technology in remote monitoring system allowing a reliability increase in operational convenience.

Dentre as fontes de energia renováveis utilizadas para geração de energia elétrica a que mais se destaca atualmente e a energia eólica. 0 crescente índice de penetração da geração eólica na matriz energética dos sistemas de potencia impõe a necessidade da revisão de conceitos anteriormente estabelecidos sobre a estabilidade de sistemas de potencia, uma vez que ainda não e perfeitamente compreendida a influencia de uma maior integração deste recurso no comportamento dos sistemas de potencia. Este trabalho tem como foco o estudo da estabilidade de sistemas com aerogeradores de velocidade fixa equipados com geradores de indução de rotor em gaiola. E estudada a estabilidade angular de um sistema de geração eólica equipado com aerogeradores desta natureza. O problema da estabilidade foi decomposto em três partes: estabilidade estática, estabilidade dinâmica e estabilidade transitória. São definidos os modelos dos componentes do aerogerador para cada um dos estudos realizados. A topologia adotada á a máquina Barramento Infinito (MBI), na qual o restante do sistema de potência a representado pelo seu equivalente de Thevenin. Esta topologia típica de analise de estabilidade de sistemas de potencia e adotada por permitir a obtenção de resultados analíticos para as analises estática e dinâmica. A analise transitória se dá através de simulações computacionais. A fim de manter um caráter mais geral para os resultados as simulações são realizados com três aerogeradores de características distintas. Os resultados obtidos permitem uma melhor compreensão da influencia sobre a estabilidade do sistema de geração eólica dos parâmetros de rede do sistema de potencia como: potencia de curto-circuito do ponto de conexão comum com o sistema de potencia, relação X/R da linha de transmissão e do capacitor de compensação de fator de potencia. / Among the renewable energy sources used to generate electric power one of the most important at this time is the wind power. The growing penetration index of wind power in the power systems energetic matrix leads to the necessity of a reevaluation of the concepts previously established about the stability of power systems, since the influence of a major integration of this resource in the behavior of power systems is not perfectly understood. This work focuses on the stability study of wind power systems equiped with fixed-speed squirrel-cage induction generators. The angular stability of a wind generation system equipped with wind generators of this nature is studied. The stability problem was decomposed in three parts: static stability, dynamic stability and transient stability. The models of the components of the wind generator are defined for each of the studies. The considered topology was an Induction Generator Infinite Bus System (IBM), where the rest of the power system is represented by it’s Thévenin equivalent. This is a typical topology in power systems stability analysis and is adopted in this work aiming at obtaining analytical and general stability results. The transient analysis is performed by computer simulations. In order to provide more generatily to the stability results, all simulations are conducted with three wind generators with distinct characteristics. The obtained results allow a better comprehension about the influence, on the stability of wind power systems, of power system network parameters as: short-circuit capacity of the common connection point with the power system, the X/R relation of the transmission line and the power factor compensation capacitor.

Esse trabalho propõe a investigação da geometria dos contornos internos de eixos vazados para aerogeradores quando aplicados mandris com diferentes diâmetros ao longo de seu comprimento no forjamento incremental em matriz aberta. Tem-se por finalidade a fabricação de um mandril que proporcione à peça forjada formato mais perto do formato final proposto. Foram estudados através do uso de simulações numéricas computacionais com o software Simufact.forming 12 e ensaios com o material modelo plasticina possíveis geometrias de mandris, variando a angulação na região de troca de diâmetros ao longo do comprimento entre 0˚, 30˚ e 60˚, e analisados o comportamento do escoamento do material na região. Com o processo simulatório concluído, foi produzido o mandril que apresentou melhor desempenho e foram realizados testes práticos. No total, duas peças foram forjadas e analisados seus resultados. A geometria proposta da peça foi alcançada, confirmando a escolha da cinemática do processo. A temperatura do mandril foi aferida e comparada com a temperatura durante a simulação, onde no último passe, a medida foi 720°C e a simulada em torno de 620°C. As forças de forjamento apresentaram diferença entre a simulação e forjado na média de 7,6%. / This work proposes the investigation of the internal contour of hollow shafts for wind turbines when applied mandrels with different diameters along its length in incremental open-die forging. It is intended to manufacture a mandrel to provide a forged part closer to the final proposed geometry. Studies were conducted using the numerical computer simulations software Simufact.forming 12 and models of plasticine aiming possible mandrel geometries, varying the angle of the different-diameters region along the length between 0˚, 30˚ and 60˚ and analyzed the behavior of the material flow in the region. As the simulation process was concluded, the mandrel with the best performance was produced and practical tests were performed. In total, two workpieces were forged and analyzed its results. The proposed geometry was achieved, confirming the choice of process kinematics. The temperature of the mandrel was measured and compared with the temperature during the simulation at the last pass, the measurement resulted in 720°C and the simulated around 620°C. The forging forces showed differences between simulation and forging of an average of 7.6%.

AN ABSTRACT OF THE THESIS OF Mohamed A. Abuella, for the Master of Science degree in Electrical and Computer Engineering, presented on May 10, 2012, at Southern Illinois University Carbondale. TITLE:STUDY OF PARTICLE SWARM FOR OPTIMAL POWER FLOW IN IEEE BENCHMARK SYSTEMS INCLUDING WIND POWER GENERATORS MAJOR PROFESSOR: Dr. C. Hatziadoniu, The aim of this thesis is the optimal economic dispatch of real power in systems that include wind power. The economic dispatch of wind power units is quite different of conventional thermal units. In addition, the consideration should take the intermittency nature of wind speed and operating constraints as well. Therefore, this thesis uses a model that considers the aforementioned considerations in addition to whether the utility owns wind turbines or not. The optimal power flow (OPF) is solved by using one of the modern optimization algorithms: the particle swarm optimization algorithm (PSO). IEEE 30-bus test system has been adapted to study the implementation PSO algorithm in OPF of conventional-thermal generators. A small and simple 6-bus system has been used to study OPF of a system that includes wind-powered generators besides to thermal generators. The analysis of investigations on power systems is presented in tabulated and illustrative methods to lead to clear conclusions.