Stability Margins
Mostrando 13-22 de 22 artigos, teses e dissertações.
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13. Preventive control strategies for maintaining secure on-line voltage stability margins / Estrategias de controle preventivo para a manutenção de margens de segurança com relação a estabilidade de tensão em tempo real
O problema de estabilidade de tensão tem recebido uma atenção crescente dos profissionais que atuam na área de análise e operação de sistemas de potência. O aumento das interligações aliado a operação das redes com altos níveis de carregamento torna mais provável a ocorrência de incidentes que podem levá-las à instabilidade de tensão, culmi
Publicado em: 2006
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14. Estudos de um método para cálculo de ganhos da malha de controle de atitude de um lançador de satélites / Analytical method for computing the controller gains of a satellite launcher
In this work, the VLS (Satellite Launcher Vehicle) control gains are calculated applying a frozen poles technique for each 1-second interval, allowing that a linear time invariant analysis to be executed inside each time interval during all flight phases. The system control architecture is proportional-integral with derivative feedback, making the 3 gains (p
Publicado em: 2004
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15. Melhoria das margens de estabilidade de tensão no problema do pre-despacho da operação atraves de corte mínimo de carga
The new philosophy of operating electric power systems exploring their maximum power transfer capability has placed the systems close to their stability limits. Therefore, it is important to assess the distance from the equilibrium point to the system voltage stability limit, and how to keep an adequate security margin from this limit. Considering the import
Publicado em: 2003
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16. Robustness margins for global asymptotic stability in indirect field-oriented control of induction motors
A estabilidade de acionamentos por orientação de campo indireta de motores de indução quando sujeitos a erros de estimativa da constante de tempo do rotor é analisada. O artigo se concentra na estabilidade global, estendendo os resultados de []. Margens de robustez são determinadas e diretivas para projeto do laço PI de velocidade são obtidas. A meto
Sba: Controle & Automação Sociedade Brasileira de Automatica. Publicado em: 2002-09
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17. 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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18. A influencia de compensadores estaticos de reativos na estabilidade de tensão de sistemas de energia eletrica
This work presents a study of the Static Var Compensators (SVC) influence on Power System Voltage Stability problems. The dynamic interactions of load, generator and SVC, for a simple system, are investigated via dynamic modal analysis. The SVCs effects on a 39 buses system (New England) are studied by static modal analysis. The results of both cases indic
Publicado em: 2001
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19. Controle multivariavel : superficies de Riemann, diagrama de ganho e analise no espaço de frequencias
This work deals with monovariable and multivariablecontrol systems analysisthrough Riemann surfaces. It is shown that a complete Riemann surface representation has dimension four, and new representations are presented in two-dimensional and three-dimensional plots. Generalizations ofthe existing representations, like root-Iocus, gain plots, Nyquist, Bode and
Publicado em: 1997
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20. Tolerancia a inundação e aspectos demograficos de Inga affinis Dc
Although protected by legislation since 1934 the forests along river margins, i.e. Gallery Forests, are still being cut and/or burnt in the interior of the State of São Paulo. The destriction of these forests result in irreversible environmentaI damages, such as soil erosion and silting UP the rivers and water reservoirs. The preservation and management of
Publicado em: 1990
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21. Health plan competition in local markets.
OBJECTIVE: To examine the structure of local health insurance markets and the strategies health plans were using to respond to competitive pressures in local markets in 1996/1997. DATA SOURCES/STUDY SETTING: Community Tracking Study site visits conducted between May 1996 and April 1997 in 12 U.S. markets selected to be nationally representative. STUDY DESIGN
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22. Flebogamma® 5% DIF development: rationale for a new option in intravenous immunoglobulin therapy
Flebogamma® 5% dual inactivation and filtration (DIF), a new 5% liquid intravenous immunoglobulin with a stability of 2 years when stored at temperatures between 2 and 30°C, has been developed. This new product is the result of the accumulated experience provided by Flebogamma®, with more than 30 million grams administered since 1992 in Europe and the Uni
Blackwell Science Inc.