Reactive Power Control
Mostrando 37-47 de 47 artigos, teses e dissertações.
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37. ANÁLISE DO CONGESTIONAMENTO EM REDES DE TRANSMISSÃO APLICADA AO PROBLEMA DO REFORÇO DE SEGURANÇA DE TENSÃO / TRANSMISSION CONGESTION ANALYSIS APPLIED ON VOLTAGE SECURITY REINFORCEMENT PROBLEM
After a number of collapses due to the extreme use of the transmission lines, the voltage stability, or voltage security, became an important issue. This work was developed in order to contribute to a voltage security reinforcement method. The method calculates control actions to decrease the power flowing through the critical branch of the most loaded trans
Publicado em: 2003
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38. Control Strategies for Wind Turbines with Induction Generators / EstratÃgias de controle de sistemas de garaÃÃo eÃlica com mÃquinas de induÃÃo
The perspectives of a great number of accesses of wind turbines to the Brazilian electrical system have stimulated studies on the controls of these generators and the impacts that they will cause in the electrical grid. This two stages work, considered the study of control techniques of induction generators with squirrel cage type or doubly fed, when set in
Publicado em: 2003
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39. ACTUAL REACTIVE POWER CAPABILITY EVALUATION IN AN ELECTRICAL POWER PLANT / AVALIAÇÃO DA CAPACIDADE REAL DE GERAÇÃO DE POTÊNCIA REATIVA EM UMA USINA DE GERAÇÃO DE ENERGIA ELÉTRICA
They show that different generator loads produce greater heating in different parts of generator. A method is described and a software is presented to evaluate the actual reactive power capability curve considering the operating condition.This paper shows that it is possible to enlarge the reactive power capability only by knowing the actual capability limit
Publicado em: 2002
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40. VOLTAGE STABILITY REINFORCEMENT ON ELETRIC POWER SYSTEMS / REFORÇO DAS CONDIÇÕES DE ESTABILIDADE DE TENSÃO NA OPERAÇÃO DO SISTEMA ELÉTRICO
As the electric power transmission networks became more interconnected, the thermal limits of lines and transformers restrict less the power transmission. Similarly, the use of static systems of reactive power compensation increases the power transmission capacity in systems whereas before they were limited by problems of angular stability. Actually, transmi
Publicado em: 2002
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41. Recent progress in the synthesis and characterization of amorphous and crystalline carbon nitride coatings
This review summarizes our most recent findings in the structure and properties of amorphous and crystalline carbon nitride coatings, synthesized by reactive magnetron sputtering. By careful control of the plasma conditions via proper choice of process parameters such as substrate bias, target power and gas pressure, one can precisely control film structure
Brazilian Journal of Physics. Publicado em: 2000
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42. MODELAGEM DO CONTROLE DE TENSÃO PARA A AVALIAÇÃO DO CARREGAMENTO DA REDE DE TRANSMISSÃO / MODELING OF VOLTAGE CONTROL FOR THE EVALUATING OF THE TRANSMISSION SYSTEM LOADING
A falta de recursos e a questão ecológica tem limitado a expansão do sistema de transmissão. Esta realidade, em conjunto com o crescimento da carga, faz com que os sistemas elétricos trabalhem bastante carregados. Esta nova condição pode levar a situações de colapso de tensão. O desenvolvimento de métodos para a avaliação do carregamento da rede
Publicado em: 1999
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43. Um sistema de suporte ao controle de tensão e potencia reativa com processamento de conhecimento
ln the Power Transmission Systems operation, voltagej reactive power probIems can occur, any time due to contingencies andjor changes in demando However, appropriate contraI decisions are necessary in a short time, in order to improve the operating state and not to put the security and reliability of eIectric system at risk. Some of these situations can requ
Publicado em: 1993
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44. Uma contribuição ao estudo da influencia de elos CC na dinamica de sistemas CA, atraves de simulação digital
This work aims to study the effeet of HVDC systems upon the dynamie of AC systems. In this way, several models which use de power modulation an extinction angle control are considered and included into a digital transient stability programme. Apart from this, the effect or the AC system eommutation reactanee on the active and reactive AC power calculations i
Publicado em: 1986
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45. AN ANALYTICAL METHOD FOR THE HARMONIC ANALYSIS OF SATURATED REACTORS / UM MÉTODO ANALÍTICO PARA ANÁLISE HARMÔNICA DE REATORES SATURADOS
This work is concerned with the presentation of an analytical method for the harmonic analysis of three-phase saturated reactors when used for controlling voltage in power systems. The requirements for voltage control in transmission and distribution systems through the demand for reactive power are first discussed and the various types of existing compensat
Publicado em: 1979
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46. Direct measurement of free radical generation following reperfusion of ischemic myocardium.
Electron paramagnetic resonance spectroscopy was used to directly measure free radical generation in perfused rabbit hearts. Hearts were freeze-clamped at 77 degrees K during control perfusion, after 10 min of normothermic global ischemia (no coronary flow), or following post-ischemic reperfusion with oxygenated perfusate. The spectra of these hearts exhibit
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47. Role of complement in the expression of delayed-type hypersensitivity in rats: studies with cobra venom factor.
The hypothesis was tested that delayed-type hypersensitivity (DTH) to the complement-activating bacterium Listeria monocytogenes is initiated by complement-derived mediators that attract sensitized lymphocytes to reaction sites. To this end DTH and acquired resistance to L. monocytogenes were measured in rats injected with cobra venom factor, a potent inacti