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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Sistema de convers?o de energia e?lica baseado no gerador de indu??o duplamente alimentado: an?lise e contribui??o ao controle da m?quina

Taveiros, Filipe Emanuel Vieira 28 May 2014 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2015-09-28T20:11:27Z No. of bitstreams: 1 FilipeEmanuelVieiraTaveiros_DISSERT.pdf: 11147293 bytes, checksum: e0376f15955899a774d145970625a91c (MD5) / Approved for entry into archive by Elisangela Moura (lilaalves@gmail.com) on 2015-10-01T13:41:25Z (GMT) No. of bitstreams: 1 FilipeEmanuelVieiraTaveiros_DISSERT.pdf: 11147293 bytes, checksum: e0376f15955899a774d145970625a91c (MD5) / Made available in DSpace on 2015-10-01T13:41:25Z (GMT). No. of bitstreams: 1 FilipeEmanuelVieiraTaveiros_DISSERT.pdf: 11147293 bytes, checksum: e0376f15955899a774d145970625a91c (MD5) Previous issue date: 2014-05-28 / A humanidade encontra-se numa ?poca de desenvolvimento tecnol?gico sem precedentes.A ci?ncia alcan?ou e continua alcan?ando conquistas que permitem compreender cada vez mais o universo e as leis que o regem e, tamb?m, tentar coexistir sem destruir o planeta em que vivemos. Um dos principais desafios do s?culo XXI ? buscar e incrementar a gama de fontes de energias limpas, renov?veis e capazes de sustentar nosso crescimento e estilo de vida. ? dever de cada pesquisador dedicar-se e contribuir nesta corrida energ?tica. Neste contexto, a energia e?lica se apresenta como uma das grandes promessas para o futuro da gera??o el?trica. Apesar de ser um pouco mais antiga que outras fontes de energia renov?vel, a gera??o e?lica ainda apresenta um vasto campo para melhoramento. O desenvolvimento de novas t?cnicas de controle do gerador juntamente com o desenvolvimento de laborat?rios de pesquisa especializados em gera??o e?lica formam um dos pontos chave para aumentar o rendimento, a efici?ncia e a confiabilidade do sistema. O controle apropriado do esquema de conversores back-to-back permite que as turbinas e?licas baseadas no gerador de indu??o duplamente alimentado (DFIG) operem no modo de velocidade vari?vel, cujos benef?cios incluem m?xima extra??o de pot?ncia, inje??o de pot?ncia reativa e redu??o de estresse mec?nico. O conversor do lado do rotor fornece controle de pot?ncia ativa e reativa injetada na rede, enquanto que o conversor do lado da rede fornece o controle da tens?o no link CC e fluxo de pot?ncia bi-direcional. A estrutura de controle convencional utiliza controladores PI com compensa??o feed-forward dos termos de acoplamento cruzado. Como desvantagens, esta t?cnica de controle apresenta sensibilidade a incertezas do modelo e, tamb?m, a compensa??o de termos din?micos acoplados resulta em uma estrat?gia de controle concorrente. Por isso, para superar estes problemas e eliminar os termos de acoplamento cruzado, ? utilizado uma estrutura de controle robusta com realimenta??o de estados baseada no princ?pio do modelo interno,visando melhorar o acionamento do gerador bem como o seu comportamento din?mico durante varia??es abruptas na velocidade do vento. O desempenho da t?cnica de controle proposta para o controle do gerador DFIG ser? comparado ao da abordagem de controle convencional sob condi??es de vento est?veis e rajadas. Um emulador de turbina e?lica foi desenvolvido para recriar em laborat?rio uma condi??o realista e submeter o gerador a v?rias condi??es de velocidade do vento. / The humanity reached a time of unprecedented technological development. Science has achieved and continues to achieve technologies that allowed increasingly to understand the universe and the laws which govern it, and also try to coexist without destroying the planet we live on. One of the main challenges of the XXI century is to seek and increase new sources of clean energy, renewable and able to sustain our growth and lifestyle. It is the duty of every researcher engage and contribute in this race of energy. In this context, wind power presents itself as one of the great promises for the future of electricity generation . Despite being a bit older than other sources of renewable energy, wind power still presents a wide field for improvement. The development of new techniques for control of the generator along with the development of research laboratories specializing in wind generation are one of the key points to improve the performance, efficiency and reliability of the system. Appropriate control of back-to-back converter scheme allows wind turbines based on the doubly-fed induction generator to operate in the variable-speed mode, whose benefits include maximum power extraction, reactive power injection and mechanical stress reduction. The generator-side converter provides control of active and reactive power injected into the grid, whereas the grid-side converter provides control of the DC link voltage and bi-directional power flow. The conventional control structure uses PI controllers with feed-forward compensation of cross-coupling dq terms. This control technique is sensitive to model uncertainties and the compensation of dynamic dq terms results on a competing control strategy. Therefore, to overcome these problems, it is proposed in this thesis a robust internal model based state-feedback control structure in order to eliminate the cross-coupling terms and thereby improve the generator drive as well as its dynamic behavior during sudden changes in wind speed. It is compared the conventional control approach with the proposed control technique for DFIG wind turbine control under both steady and gust wind conditions. Moreover, it is also proposed in this thesis an wind turbine emulator, which was developed to recreate in laboratory a realistic condition and to submit the generator to several wind speed conditions.

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