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Design of a Vernier Permanent Magnet Wind GeneratorDudley, Darren Richard 20 January 2021 (has links)
The rise in popularity of renewable energy solutions, in particular wind energy systems, has resulted in a greater demand for low-speed direct-drive machines. The Vernier machine has inherent properties such as high torque density, sinusoidal induced voltages and low torque ripple which makes it suitable for low-speed direct-drive wind applications. Additionally, its mechanical structure is as simple as a conventional permanent magnet (PM) machine, whilst eliminating the need for a mechanical gearbox. The research problem addressed by this dissertation relates to the assessment of the Vernier permanent magnet (VPM) machine topology for direct-drive wind applications. It aims to outline a sizing, detailed design and analysis approach for a three-phase VPM wind generator. Furthermore, a comparative study is conducted using two different rotor types and two different stator types, namely; spoke-type and surface-mounted and fractional slot and integral slot respectively. Vernier theory is used to size the designs after which 2D Finite Element Analysis (FEA) simulations are used to analyse and validate the designs. The main outcome of the comparative study is an assessment of the suitability of four topologies for the direct-drive wind application. The design is assessed on parameters which are critical for wind turbine functionality; namely efficiency, torque ripple, torque density and material consumption. The most suitable of the topologies is selected for prototyping. The rotor is made more robust by adding structural features which mechanically secure laminations and PMs to the shaft. The FEA analysis of the prototype showed favourable performance characteristics, albeit with a small cost in power density. The prototype was -thus manufactured with further mechanical reinforcements made to the bearing system. Experimental results reveal the presence of a defect in the windings. Parameters which are dependent on the winding design are much lower than the analytical and FEA values. These parameters include resistance, inductance, and back-EMF. Further work should look into determining the root cause of the prototype defects.
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Analysis and design of a double-sided rotor iron-cored radial flux permanent magnet synchronous wind turbine generatorVan Wijk, Johannes Hendrik 03 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: The electromagnetic and mechanical design aspects of an optimally designed double-sided rotor radial flux permanent magnet wind generator with non-overlap iron-cored stator windings are analysed in this thesis. The generator topology proposed in this study aims to reduce the strength demand on the generator structural support, caused by the magnetic attraction forces between the rotor and stator iron components, and in so doing reducing the overall generator mass. The proposed design has very good cooling properties. Compared to a conventional iron-cored permanent magnet generator and an air-cored permanent magnet generator, the double-sided rotor iron-cored topology performs the best with reference to mass and efficiency. / AFRIKAANSE OPSOMMING: Die elektro-magnetiese en meganiese ontwerp-aspekte van ‘n optimal ontwerpte tweesydige rotor radial-vloed permanente magneet windgenerator met nie-oorvleulende ysterkern statorwindings word in hierdie tesis ontleed. Met die generator topologie wat in hierdie studie voorgestel word, word beoog om die strukturele materiaal wat vir die generator benodig is te verminder. Die magnetise aantrekkingskragte tussen die yster komponente van die rotor en stator word dus aangespreek in hierdie studie, om sodoende ook die algehele massa van die permanente magneet generator te verminder. Die voorgestelde tweesydige-rotor ontwerp het baie goeie verkoelings eienskappe en het ‘n kleiner massa en hoër effektiwiteit as beide ‘n konvensionele ysterkern generator met ‘n enkelsydige-rotor en ‘n tweesydige-rotor lugkern permanente magneet generator met dieselfde drywingsvermoë.
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AvaliaÃÃo do Rendimento de Unidade de Bombeamento de Ãgua Acionada por um Gerador EÃlico de Pequeno Porte / Performance evaluation of water pumping unit powered by a small wind turbineMendeleyev Guerreiro Ferreira 27 March 2009 (has links)
Esta dissertaÃÃo de mestrado apresenta um sistema para bombeamento de Ãgua utilizando um gerador eÃlico autÃnomo de pequeno porte, instalado em frente ao aÃude do Campus da UFC. A potÃncia do gerador à de 1 kW e o mesmo utiliza a tecnologia de Ãmà permanente garantindo vantagens como: menores perdas no rotor, menor aquecimento e o alcance de maiores rendimentos. AlÃm do gerador eÃlico, o sistema à composto por um conjunto motor-bomba centrÃfuga de 0,5 cv de potÃncia, um medidor de vazÃo, um medidor de pressÃo, um analisador de energia que registra valores de grandezas elÃtricas (corrente, tensÃo, potÃncia), um datalogger para coleta de dados e um anemÃmetro de conchas para mediÃÃo de vento. O projeto consiste em determinar o rendimento deste sistema para as condiÃÃes de vento do local da instalaÃÃo, a partir de dados coletados durante os meses de maio e julho de 2008. Os resultados demonstram que em apenas cerca de 10,97% do total de dias referentes ao mÃs de maio e cerca de 54,57% do total de dias do mÃs de julho, o conjunto motor-bomba foi acionado pelo gerador eÃlico e que os rendimentos globais variam entre 0,41 e 0,74%. Observando os valores de vazÃo encontrados, quando comparados com a curva caracterÃstica da bomba utilizada, percebe-se uma sub-utilizaÃÃo da mesma, principalmente no mÃs de maio. / This work presents a system for water pumping using an independent small wind generator, installed in the UFCÂs Campus. The generatorâs power is 1 kW and uses a permanent magnet technology providing advantages such as: lower losses in the rotor, lower heating and achieving higher yields. Besides the wind generator, the system consists of centrifugal pump-motor assembly 0,5 cv of power, a flow meter, a pressure meter, an energy analyzer that records the electrical data (current, voltage, power), a datalogger for data collection and a shell anemometer for measuring of wind speed. The project consists in determining the performance of this system for the local wind conditions, from data collected during the months of May and July 2008. The results show that in only about 10,97% of total days for the month of May and about 54,57% of the total days of July, the pump-motor was triggered by the wind generator and the global yields ranging between 0,41 to 0,74%. Observing the flow values found when compared with the characteristic curve of the pump used, there is a perceived under-utilization of the same, especially in May.
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Short circuit modeling of wind turbine generators2013 August 1900 (has links)
Modeling of wind farms to determine their short circuit contribution in response to faults is a crucial part of system impact studies performed by power utilities. Short circuit calculations are necessary to determine protective relay settings, equipment ratings and to provide data for protection coordination.
The plethora of different factors that influence the response of wind farms to short circuits makes short circuit modeling of wind farms an interesting, complex, and challenging task. Low voltage ride through (LVRT) requirements make it necessary for the latest generation of wind generators to be capable of providing reactive power support without disconnecting from the grid during and after voltage sags. If the wind generator must stay connected to the grid, a facility has to be provided to by-pass the high rotor current that occurs during voltage sags and prevent damage of the rotor side power electronic circuits. This is done through crowbar circuits which are of two types, namely active and passive crowbars, based on the power electronic device used
in the crowbar triggering circuit. Power electronics-based converters and controls have become an integral part of wind generator systems like the Type 3 doubly fed induction generator based wind generators. The proprietary nature of the design of these power electronics makes it difficult to obtain the necessary information from the manufacturer to model them accurately. Also, the use of power electronic controllers has led to phenomena such as sub-synchronous control interactions (SSCI) in series compensated Type 3 wind farms which are characterized by non-fundamental frequency oscillations. SSCI affects fault current magnitude significantly and is a crucial factor that cannot be ignored while modeling series compensated Type 3 wind farms.
These factors have led to disagreement and inconsistencies about which techniques are appropriate for short circuit modeling of wind farms. Fundamental frequency models like voltage behind transient reactance model are incapable of representing the majority of critical wind generator fault characteristics such as sub-synchronous interactions. The Detailed time domain models, though accurate, demand high levels of computation and modeling expertise. Voltage dependent current source modeling based on look up tables are not stand-alone models and provide only a black-box type of solution.
The short circuit modeling methodology developed in this research work for representing a series compensated Type 3 wind farm is based on the generalized averaging theory, where the system variables are represented as time varying Fourier coefficients known as dynamic phasors. The modeling technique is also known as dynamic phasor modeling. The Type 3 wind generator has become the most popular type of wind generator, making it an ideal candidate for such a modeling method to be developed.
The dynamic phasor model provides a generic model and achieves a middle ground between the conventional electromechanical models and the cumbersome electromagnetic time domain models. The essence of this scheme to model a periodically driven system, such as power converter circuits, is to retain only particular Fourier coefficients based on the behavior of interest of the system under study making it computationally efficient and inclusive of the required frequency components, even if non-fundamental in nature. The capability to model non-fundamental frequency components is critical for representing sub-synchronous interactions. A 450 MW Type 3 wind farm consisting of 150 generator units was modeled using the proposed approach. The method is shown to be highly accurate for representing faults at the point of interconnection of the wind farm to the grid for balanced and unbalanced faults as well as for non-fundamental frequency components present in fault currents during sub-synchronous interactions. Further, the model is shown to be accurate also for different degrees of transmission line compensation and different transformer configurations used in the test system.
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Διερεύνηση της λειτουργίας συστήματος διασύνδεσης ανεμογεννήτριας με το δίκτυο χαμηλής τάσης - Κατασκευή διάταξης ανύψωσης τάσηςΓκαρτζώνης, Ιωάννης 07 June 2013 (has links)
Η παρούσα διπλωματική εργασία πραγματεύεται τη μελέτη μίας διάταξης ανεμογεννήτριας 1kW με σύγχρονη μηχανή μόνιμων μαγνητών και με ανορθωτική γέφυρα διόδων στην έξοδό της καθώς και τη διασύνδεση αυτής με το εναλλασσόμενο δίκτυο χαμηλής τάσης. Επιπρόσθετα πραγματεύεται την κατασκευή του ανυψωτή τάσης που ενσωματώνεται στην εν λόγω τοπολογία. Η εργασία αυτή εκπονήθηκε στο Εργαστήριο Ηλεκτρομηχανικής Μετατροπής Ενέργειας του Τμήματος Ηλεκτρολόγων Μηχανικών και Τεχνολογίας Υπολογιστών της Πολυτεχνικής Σχολής του Πανεπιστημίου Πατρών.
Απώτερος σκοπός της εργασίας είναι η συνολική κατασκευή μίας διάταξης δύο βαθμίδων για τη διασύνδεση της ανεμογεννήτριας με το δίκτυο χαμηλής τάσης. Οι διατάξεις αυτές περιλαμβάνουν μια πρώτη βαθμίδα ανύψωσης της τάσης της ανεμογεννήτριας μέσω της οποίας εκτελείται ένας αλγόριθμος εύρεσης του σημείου μέγιστης ισχύος της ανεμογεννήτριας (MPPT) και μια δεύτερη βαθμίδα που μετατρέπει τη συνεχή τάση σε εναλλασσόμενη (αντιστροφέας) και διατηρεί σταθερή την τάση στον πυκνωτή διασύνδεσης που παρεμβάλλεται μεταξύ των δύο βαθμίδων με έλεγχο της ενεργού ισχύος που εγχέει στο δίκτυο, ενώ παράλληλα παράγει ρεύμα συμφασικό με την τάση του δικτύου (μοναδιαίος συντελεστής ισχύος). Η πρώτη βαθμίδα αποτελεί αντικείμενο της παρούσας διπλωματικής εργασίας, ενώ η δεύτερη υλοποιήθηκε στα πλαίσια της διπλωματικής εργασίας του συναδέλφου Γ. Πυρρή.
Αρχικά παρουσιάζονται τα πλεονεκτήματα και οι δυσκολίες στην εκμετάλλευση ανανεώσιμων πηγών ενέργειας και ιδιαίτερα της αιολικής, ενώ παρατίθενται και συγκρίνονται οι τεχνολογίες διασύνδεσης ανεμογεννητριών στο δίκτυο χαμηλής, μέσης και υψηλής τάσης στοχεύοντας στο να δοθεί στον αναγνώστη μια σφαιρική άποψη του υπό μελέτη θέματος.
Στη συνέχεια παραθέτουμε μια θεωρητική ανάλυση όλων των εμπλεκομένων μονάδων της τοπολογίας. Ιδιαίτερη βαρύτητα δίνεται στην ανάλυση της λειτουργίας του ανυψωτή τάσης. Επόμενο βήμα αποτέλεσε η διαστασιολόγηση ολόκληρου του υπό μελέτη συστήματος, η μελέτη μεθόδων ελέγχου μέγιστης απομάστευσης ισχύος και η προσομοίωση του συστήματος.
Τέλος αναλύουμε τη διαδικασία υλοποίησης του ανυψωτή τάσης και παραθέτουμε παλμογραφήματα και μετρήσεις που προέκυψαν από τα πειράματα που διενεργήσαμε μετά την ολοκλήρωση της κατασκευής σε εργαστηριακό περιβάλλον. / The current thesis deals with the study of a module of a wind generator 1kW with a synchronous permanent magnet machine and a diode rectifier in its output and its interconnection to the low voltage AC grid. Furthermore the thesis deals with the construction of the boost converter that is connected to this topology. This thesis was conducted in the Laboratory of Electromechanical Energy Conversion, Department of Electrical and Computer Engineering School of Engineering, University of Patras.
The outer purpose of this study is the construction of a two-stage topology for the interconnection of the wind genereator to the low voltage grid. The topology consist of a first stage that boosts the voltage of the wind generator while a maximum power point tracking algorithm (MPPT) is executed and of a second stage that converts the direct voltage to alternative (inverter) and maintains the voltage of the link capacitor that is between the two stages with control of the active power that is injected to the grid, while producing current that has the same phase as the voltage grid (unitary power coefficient). The first stage is object of the current thesis, while the second was constructed in the thesis of workmate G.Pyrris.
Initially, are represented the advandages and disadvantages of the utilization of the renewable energy sources and especially the wind energy, while different technologies for interpolation of wind generators to the low, medium and high voltage grid are represented and compared in order to give to the reader a global idea of the subject.
Consequently a theoretical analysis of all the related modules is cited. Special reference was given to the analysis of the boost converter. Next step was the dimensioning of the whole system, the study of maximum power point tracking methods and the simulation of the system.
Finally, the procedure of the boost converter’s construction is elaborated and pulse waves
and measurements that were extracted during the experiments that were conducted in laboratory environment are represented .
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Avaliação do uso da transmissão continuamente variável (cvt) em geradores eólicos de médio porte ligados a rede de distribuição de energia elétricaSilva, Carlos Eduardo Freitas da January 2016 (has links)
Orientador: Prof. Dr. Julio Carlos Teixeira / Dissertação (mestrado) - Universidade Federal do ABC. Programa de Pós-Graduação em Energia, 2016. / As turbinas eólicas de velocidade fixa são a tecnologia mais tradicional, robusta e de baixo custo para conversão de energia eólica em eletricidade, em especial para potências abaixo do MW. No entanto, nestes geradores a variação da velocidade do vento é refletida como uma mudança na potência de saída do gerador de energia eólica. Esta característica tem duas grandes desvantagens: a baixa eficiência na operação do gerador fora do ponto máximo de energia e o alto nível da cintilação na rede de distribuição de energia. O uso de transmissão continuamente variável (CVT) no gerador de energia eólica permite a dissociação entre a variação da velocidade do vento e da potência de saída do gerador. O objetivo do presente projeto é desenvolver um sistema de controle capaz de usar esta característica de desacoplamento, a fim de aumentar a eficiência do gerador de energia eólica e diminuir os níveis de cintilação na rede de energia. O controle proposto foi verificado em um modelo de gerador, CVT e a rede elétrica de distribuição. Os resultados mostram que o sistema de controle proposto pode aumentar a energia eólica convertida com um baixo efeito de cintilação no sistema de energia. / The fixed speed wind turbines are the most traditional, robust and low cost technology for wind energy conversion into electricity, particularly for power rating below MW. However, in these generators the wind speed variation is reflected as a change in the power output of the wind generator. This characteristic has two major disadvantages: the low efficiency at generator operation outside the maximum energy point, and the high level of the flicker in the power distribution grid. The use of continuously variable transmission (CVT) in the wind generator allows decoupling between the wind speed variation and the output power of the generator. The aim of this project is to develop a control system able to use this decoupling characteristic in order to increase the efficiency of the wind generator and decrease the flicker levels in the power grid. The proposed control was verified in a model of generator, CVT and the distribution power grid. The results show that the proposed control system can increase the wind energy converted with a low flicker effect in the power system.
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Novo MÃtodo e Modelos Para Estudos de Fluxo de PotÃncia e de Curto-circuito / New method and models for power flow and short circuit studies.Adriano Aron Freitas de Moura 18 January 2013 (has links)
nÃo hà / Este trabalho apresenta um novo mÃtodo de fluxo de potÃncia linear o fluxo de potÃncia linear V-teta tambÃm apresenta uma nova modelagem do gerador sÃncrono para estudos de fluxo de potÃncia trifÃsico em redes de distribuiÃÃo desequilibradas radiais e uma modelagem do gerador eÃlico sÃncrono em componentes de fase para estudos de curto-circuito em sistemas de distribuiÃÃo radiais Os resultados revelam que 1) Para o fluxo de potÃncia linear V-teta à possÃvel o cÃlculo de forma desacoplada e linear dos fluxos de potÃncia ativa e reativa no sistema Assim os erros obtidos com o fluxo de potÃncia linear V-teta sÃo em geral menores que os erros obtidos no mÃtodo clÃssico de fluxo de potÃncia CC e espera-se que o mesmo seja usado em muitas aplicaÃÃes onde o mÃtodo clÃssico de fluxo de potÃncia CC à atualmente utilizado 2) Uma nova modelagem à proposta considerando o gerador sÃncrono diretamente conectado a rede elÃtrica Uma outra modelagem jà existente na literatura considerando a conexÃo do gerador atravÃs de retificador e inversor tambÃm à usada As duas modelagens sÃo utilizadas para a realizaÃÃo de estudos de impacto dos sistemas de excitaÃÃo dos geradores sÃncronos em sistemas de distribuiÃÃo com modelagem trifÃsica Os resultados sÃo obtidos utilizando-se o sistema IEEE-13 barras A modelagem do gerador sÃncrono em componentes de
fase sob condiÃÃes desequilibradas permite: a) calcular as injeÃÃes ou consumo de potÃncias ativa/reativa de cada fase na mÃquina, b) simular o gerador sÃncrono como barra do tipo PQ e como barra do tipo PV Juntamente com esses estudos uma anÃlise inÃdita e detalhada de desequilÃbrio de tensÃo inclusive com uma demonstraÃÃo matemÃtica à apresentada 3) A representaÃÃo em componentes de fase do gerador eÃlico sÃncrono nos cÃlculos de faltas de sistemas de distribuiÃÃo
radiais obtÃm resultados mais precisos do que o mÃtodo tradicional das componentes simÃtricas uma vez que valores de impedÃncias mÃtuas de diferentes valores podem ser considerados na anÃlise do sistema / This thesis presents a new method of linear power flow linear power flow V-theta it also presents a new model of synchronous generator for power flow studies in three phase unbalanced radial distribution networks and modeling of wind synchronous generator in phase components for studies of short-circuit in radial distribution systems The results reveal that 1) For the linear power flow V-theta is possible to calculate like a linear and uncoupled form the active and reactive power flows in the system Thus the errors obtained with the linear power flow V-theta are usually
smaller than the errors obtained in classical method of DC power flow and it is expected that the linear power flow V-theta can be used in many applications where the classical method of DC power flow is currently used 2) A new model is proposed, considering the synchronous generator directly connected to the power grid Another existing literature modeling considering the connection from the generator through rectifier and inverter is also used The two modeling are used to perform impact studies of synchronous generators excitation systems for distribution systems with
three-phase modeling The results are obtained using the IEEE 13 bus - test system The modeling of synchronous generator in phase components under unbalanced conditions allow: a) calculate the active / reactive power injections in each phase of the machine b) simulate the synchronous generator as PQ bus-type and as PV bustype Along with these studies an unprecedented and detailed analysis of voltage
unbalance including a mathematical proof is presented 3) the representation of synchronous windmill generators in phase components calculations in short-circuits of radial distribution systems get more accurate results than the traditional method of symmetrical components since values of mutual impedances of different values can be considered in the analysis of the system
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A Study on Wind Turbine Low Voltage Ride Through Capability Enhancement by STATCOM and DVRLin, Chih-peng 05 February 2010 (has links)
When more induction generator based wind farms are integrated into the power system, the system voltage dips and stability problems may arise due to the draw of reactive power by induction generators. The power system short-circuit event induced wind turbine trips could result in power imbalance and lead to power system instability. This thesis studies the influence of two compensation techniques on the wind turbine low voltage ride-through (LVRT) capability. One of which is based on a parallel compensation by a static synchronous compensator (STATCOM), and the other one is a series compensation by a dynamic voltage restorer (DVR). In this study, Matlab tools and models are used to simulate an active-stall controlled fixed-speed induction generator connected to a power system. Two system configurations are used to simulate three phase faults and compare the improvement of wind turbine LVRT capability due to the two studied compensation techniques. Simulation results indicate that wind turbine compensated by DVR would have better LVRT performance than that by STATCOM in dealing with the low voltage situations due to system faults.
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Otimiza??o de sistema de bombeamento com energia e?lica: sistema de bombeamento de S?o Gabriel/BABruni, Carlos D?alexandria 24 January 2007 (has links)
Made available in DSpace on 2014-12-17T14:58:25Z (GMT). No. of bitstreams: 1
CarlosAB.pdf: 1249717 bytes, checksum: c205c3ac7994f2c6d8251901cda8facb (MD5)
Previous issue date: 2007-01-24 / After the Protocol of Kyoto and of the ECHO 92 - Rio de Janeiro, the attentions of the world focus to the preservation of the environment and of the maintainable use of the
natural resources. People were looking for preserving environment for the future generations. Ever since, solutions are looked for the supply of energy in its more acquaintances
forms and the substitution of the use of fossil fuels for the such alternative forms as: Photovoltaics, solar heat systems for water, wind , bio-diesel, etc. and in this context the
Company of Engineering of the State of Bahia - Cerb changed a diesel pumping system by an wind one, It?s the first community system of this nature in Bahia. Facing
problems with the model, a Cerb involved the academic segment of the Federal Center of Technological Education of Bahia Cefetba looking for a solution. This work intends to demonstrate the possibilities of optimization of the pumping
communit system that supply water to approximately 50 people in the place of Rom?o, municipal district of S?o Gabriel-Ba. Technical reports were published in AGRENERGD2004-Unicamp SP and Scientific Magazine ETC,Cefetba, 2005.
A simulation of the increase of energy is presented for heights of 15 and 20m, considering the eletromecanical balance from the pumping energy to the wind turbine. From the accomplished bibliographical revision, we emphasized the mechanical aspects of the engineering once in UFRN, those studies concentrate on the Department of Mechanical Engineering while, in others eletroelectronic are more emphasized. Finally, documents that we judged important were enclosed for the perfect understanding of this work / A partir do Protocolo de Kyoto e da ECO 92- Rio de Janeiro, as aten??es do mundo est?o voltadas para a preserva??o do meio ambiente e do uso sustent?vel dos recursos
naturais, preservando-os para as gera??es futuras. Desde ent?o, buscam-se solu??es para o suprimento de energia nas suas mais conhecidas formas e a substitui??o do uso de
combust?veis f?sseis pelas formas alternativas tais como solar fotovoltaica, termo-solar, e?lica, bio-diesel, etc. e neste contexto a Companhia de Engenharia do Estado da Bahia
(Cerb) substituiu um sistema de bombeamento com moto-bomba a ?leo diesel por um sistema de bombeamento com energia e?lica, primeiro sistema coletivo desta natureza.
Diante dos problemas surgidos, partiu-se para a solu??o envolvendo o segmento acad?mico do Centro Federal de Educa??o Tecnol?gica da Bahia Cefet-BA. Este
trabalho pretende demonstrar as possibilidades de otimiza??o do sistema de bombeamento comunit?rio que atende aproximadamente 50 pessoas na localidade de Rom?o, munic?pio de S?o Gabriel-Ba, tendo seus relat?rios t?cnicos publicados no AGRENERGD2004-Unicamp SP e Revista Cient?fica ETC, Cefet-BA, 005. ? apresentada uma simula??o da disponibilidade energ?tica para alturas de 15m e 20m,
considerando o balan?o eletromec?nico desde o bombeamento at? o conversor e?lico. Da revis?o bibliogr?fica realizada, optou-se pela ?nfase aos aspectos mec?nicos da
engenharia uma vez que na UFRN, esses estudos se concentram no Departamento de Engenharia Mec?nica enquanto que, em outras, os aspectos eletro-eletr?nicos s?o mais enfatizados. Finalmente, foram anexados documentos considerados importantes para a perfeita compreens?o deste trabalho
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Optimal topology and critical evaluation of slip synchronous permanent magnet wind generator / Optimale topologie en kritiese evaluering van 'n glip sinchroon permanent magneet wind generatorPotgieter, Johannes Hendrik Jacob 04 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: In this study the recently proposed slip-synchronous permanent magnet generator (SS-PMG), is
considered as an alternative to other wind generator topologies. The SS-PMG is connected directly
to the grid without the need for a power electronic converter and it can also be connected directly
to the turbine without a gearbox. Due to the SS-PMG requiring no gearbox or power electronic
converter it is evident that this type of generator have a significant advantage regarding reduced
maintenance and operation costs. The SS-PMG consist of two integrated permanent magnet generating
units, a directly turbine connected slip permanent magnet generator (slip-PMG) and a directly
grid connected permanent magnet synchronous generator (PMSG). In this, study many of the implementation
aspects of the SS-PMG are addressed. It is found that the short-circuit torque and
current profiles of both the slip-PMG and PMSG are significantly influenced by the end-winding
inductance and PM end-effects. A new analytical method is proposed for the calculation of the
end-winding inductance in this study and a new approach is devised to take the PM end-effects
into account. A very important aspect considered in this thesis, is the stability of the SS-PMG
connected directly to the grid regarding turbine, generator and grid voltage disturbances, which
influences the design of the PMSG and slip-PMG units. Furthermore, it is important that the final
SS-PMG design comply to the relevant grid code specifications. For both the PMSG and slip-PMG
an extensive design optimisation is done, with several novel wind generator concepts introduced.
In this study the dynamic behaviour, grid connection aspects and operational principles of the SSPMG
are verified by means of practical tests in the laboratory and for the SS-PMG interfaced with
an existing 15 kW wind turbine system in the field. / AFRIKAANSE OPSOMMING: In hierdie studie word die onlangs voorgestelde, glip-sinchroon permanent magneet generator (GSPMG),
oorweeg as ’n alternatief vir ander wind generator topologieë. Die GS-PMG word direk
aan die netwerk gekonnekteer sonder die nodigheid van ’n drywingselektroniese omsetter en dit kan
ook direk aan die turbine gekoppel word sonder ’n ratkas. Omdat die GS-PMG geen ratkas of
drywingselektroniese omsetter benodig nie, is dit duidelik dat hierdie tipe generator ’n geweldige
voordeel het rakende verminderde onderhoud en operasionele kostes. Die GS-PMG bestaan uit twee
geïntegreerde permanent magneet generator eenhede, ’n direkte turbine gekoppelde glip permanent
magneet generator (glip-PMG) en ’n direkte netwerk gekonnekteerde permanent magneet sinchroon
generator (PMSG). In hierdie studie word baie van die implementerings aspekte van die SS-PMG
aangeraak. Daar word gevind dat die kortsluit draaimoment en stroom profiele van beide die glip-
PMG en PMSG geweldig deur die end-wikkeling induktansie en PM randeffekte beïnvloed word.
Dus, word ’n nuwe analitiese metode voorgestel vir die uitwerk van die end-wikkeling induktansie
in hierdie studie en ’n nuwe benadering word voorgestel om die PM randeffekte in ag te neem. ’n
Baie belangrike aspek om te oorweeg in hierdie tesis, is die stabiliteit van die GS-PMG direk aan die
netwerk gekoppel rakende turbine, generator en netwerkspanning steurnisse, wat die ontwerp van
die PMSG en glip-PMG eenhede beïnvloed. Dit is ook belangrik dat die finale SS-PMG ontwerp
voldoen aan die relevante netwerkkode spesifikasies. Vir beide die PMSG en glip-PMG word ’n
deeglike ontwerpsoptimering gedoen, met talle nuwe wind generator konsepte voorgestel. In hierdie
studie word die dinamiese gedrag, netwerk konneksie aspekte en operasionele kenmerke van die GSPMG
geverifieer met behulp van praktiese toetse in die laboratorium en vir die SS-PMG geïntegreer
met ’n bestaande 15 kW wind turbine stelsel in die veld.
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