Reactive Power Control
Mostrando 25-36 de 47 artigos, teses e dissertações.
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25. CONTRIBUIÇÃO AO ESTUDO DA MÁQUINA ASSÍNCRONA TRIFÁSICA DUPLAMENTE ALIMENTADA APLICADA A AEROGERADORES DE VELOCIDADE VARIÁVEL
This work presents the analysis and implementation of a vector control applied to Doubly-Fed Induction Generators (DFIG) used in grid connected wind turbines. DFIGs are nowadays the more widely used concept for grid connected wind turbine, especially for rated power above 1 MW. The main reason is the low rotor PWM power converter rating. The present work dea
Publicado em: 2006
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26. Active Power Filters for current harmonics and reactive power compensation / Filtros Ativos de PotÃncia para CompensaÃÃo de HarmÃnicos de Corrente e PotÃncia Reativa
A popularizaÃÃo dos componentes eletrÃnicos e o conseqÃente aparecimento de novas tecnologias impulsionaram o surgimento de problemas na qualidade da energia da rede elÃtrica. O principal objetivo dessa dissertaÃÃo à estudar as propostas de compensaÃÃo das distorÃÃes nas correntes da rede elÃtrica geradas pela presenÃa de cargas que contÃm um
Publicado em: 2006
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27. Three-phase shunt active power filter driven to several functions â theoretical and practical aspects and electronic ballast with high power factor: contributions to optimization of power quality / Filtro ativo de potÃncia trifÃsico paralelo comandado para vÃrias funÃÃes â aspectos teÃricos e prÃticos e reator eletrÃnico alto FP : contribuiÃÃes a otimizaÃÃo da qualidade de energia
This work constitutes an important contribution to the study (analysis, design and practical implementation) of one of the types active power conditioners mentioned at technical literature, as three-phase shunt active power filter. Besides the several theoretical and practical aspects of this structure functioning as active power filter, it is emphasized tha
Publicado em: 2006
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28. Uma proposta de controle de paralelismo de inversores com a rede elétrica utilizando-se a técnica de realimentação de fase
Este trabalho apresenta um controlador de fluxos de potência ativa e reativa aplicado ao paralelismo de um inversor com a rede elétrica. Uma malha adicional de controle é inserida a um controlador convencional, o qual é baseado nas curvas características de potência ativa versus freqüência e potência reativa versus tensão. Essa malha utiliza a real
Publicado em: 2006
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29. Optimum sizing of units of generation distributed in radial systems of distribution through techniques of nonlinear programming. / Ajuste ótimo da potência inserida por unidades de geração distribuída em alimentadores de média tensão
The optimum sizing of units of Distributed Generation is a problem to which this formulation takes in consideration the reduction of losses in the distribution lines, the voltage control, the capacity (in MW) of the units respecting the operational limits of the system. The main objective of the sizing process is to determine the active and reactive power le
Publicado em: 2006
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30. Uma proposta de controle de paralelismo de inversores com a rede elÃtrica utilizando-se a tÃcnica de realimentaÃÃo de fase
Este trabalho apresenta um controlador de fluxos de potÃncia ativa e reativa aplicado ao paralelismo de um inversor com a rede elÃtrica. Uma malha adicional de controle à inserida a um controlador convencional, o qual à baseado nas curvas caracterÃsticas de potÃncia ativa versus freqÃÃncia e potÃncia reativa versus tensÃo. Essa malha utiliza a real
Publicado em: 2006
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31. MINIMIZING THE COST OF SERVICE OF POWER REACTIVE GENERATING PROVIDED BY TAKING INTO ACCOUNT A RESERVE POWER / MINIMIZAÇÃO DO CUSTO DO SERVIÇO DE POTÊNCIA REATIVA FORNECIDA PELOS GERADORES LEVANDO EM CONTA A RESERVA DE POTÊNCIA
In the operation of the power transmission system the problems of voltage/reactive power can occur at any time due the contingencies and/or alterations in the demand. Therefore, reactive services are necessary to perform the control in relatively small time periods to improve the operation state and avoid the degradation of the security and the reliability o
Publicado em: 2005
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32. Estudo de potência reativa, tensão, contingência e perdas em empresas de energia elétrica localizadas na Grande São Paulo
In the middle of the 20 20th th century the Brazilian electrical energy sector experienced a rapid growth, since that occasion the problem of voltage control in the transmission and distribution systems grabbed the attention of energy authorities, electrical sector offices and high voltage consumers. With the limitation of reactive power in transmission line
Publicado em: 2005
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33. Development and application of shunt active filters for three-phase four-wire systems / Estudo e aplicação de filtros ativos paralelos para sistemas trifasicos com quatro fios
Electricity power quality has gained increased importance in the past few years. The growing number of power electronicsbased loads has created a preoccupation about harrnonic distortion in electric systems. Electricity power quality is an important issue both for energy utilities and consumers. Harrnonic poIlution may cause severe problems to electricity ut
Publicado em: 2005
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34. Effects of dimethylsulfoxide, lipoic acid or ternatin pretreatment upon the oxidative stress in young rats subjected to torsion of the spermatic cord / Efeitos do pré-tratamento com dimetilsufóxido, ácido lipóico ou ternatina sobre o estresse oxidativo
The protective role of dimethylsulfoxide (DMSO), lipoic acid (LA) and ternatin (TN), known free radical scavengers and cell membrane protectants were evaluated in an experimental model of testis ischemia/reperfusion. One hundred and twenty young male Wistar rats, mean weight 172.515g, were randomized in five equal groups (GS - Sham, GC Control, GD Dimethylsu
Publicado em: 2005
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35. WIND TURBINE: MODELING, ANALYSIS AND CONTROL OF DOUBLY FED INDUCTION GENERADOR / TURBINAS EÓLICAS: MODELO, ANÁLISE, E CONTROLE DO GERADOR DE INDUÇÃO COM DUPLA ALIMENTAÇÃO
This thesis presents the main concepts and configurations used in wind turbine connected to the grid, as well as, an analysis, design and implementation of the control system for the Doubly Fed Induction Generator (DFIG). The DFIG has been selected since it is the concept frequently adopted by the wind turbine manufactures. In the thesis, it is presented a m
Publicado em: 2004
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36. Redução de perdas em redes primarias de distribuição deenergia eletrica por instalação e controle de capacitores
Technical energy losses in primary distribution networks are due to electrical resistances in lines. Due to reactance of power lines and inductive nature of some loads, part of the energy dissipated is due to reactive power that travels back and forth in lines, all the way from power sources to load points. Capacitors installed near load points can provide l
Publicado em: 2003