Small Signal Stability
Mostrando 13-24 de 35 artigos, teses e dissertações.
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13. 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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14. Projeto de controladores de amortecimento para sistemas elétricos de potência / Design of damping controllers for electric power systems
O presente trabalho propõe, como inovação, o limite superior para a energia da saída do sistema em malha fechada como índice de desempenho a ser usado no projeto de controladores robustos para amortecer oscilações eletromecânicas de baixa freqüência em sistemas de potência. A saída do sistema em malha fechada é especificada de forma que a energi
Publicado em: 2006
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15. A influencia de controladores FACTS na estabilidade de angulo a pequenas pertubações de sistemas eletricos de potencia
This master s dissertation presents an assessment of Flexible AC Transmission Systems (FACTS) controllers performance on power system small-signal angle stability improvement. The potential of the Power Sensitivity Model (PSM), an alternative approach to the classical Heffron-Phillips model (HPM) for study and analysis of poorly damped low frequency electrom
Publicado em: 2005
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16. DEVELOPMENT OF METHODOLOGY FOR CALIBRATING PIEZOELECTRIC TRANSDUCERS USED IN INTERNAL BALLISTICS FOR TRANSIENT PRESSURE MEASUREMENTS / DESENVOLVIMENTO DE METODOLOGIA DE CALIBRAÇÃO DE TRANSDUTOR PIEZELÉTRICO DE PRESSÃO UTILIZADO EM BALÍSTICA INTERNA
The current research, of armaments industry`s interest, more specifically in the quality control of ammunition lots, is related to the development of methodology for calibrating piezoelectric transducers for transient pressure measurements associated with events whose duration is of the order of milliseconds. As its main contribution, this work presents prop
Publicado em: 2004
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17. Adaptive neural control of a class of unknown nonlinear systems.
The well-known capacity of the neural networks structures to approximate functions and nonlinear systems, to any degree of accuracy, on a compact domain, has motivated its use in actual control problems where the presence of uncertainties is inevitable. Neural networks models can be used to parameterize unknown nonlinearities, hence, the linear parameterizat
Publicado em: 2002
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18. Robust controller design procedure for electromechanical oscillation damping in power systems. / Procedimento de projeto de controladores robustos para o amortecimento de oscilações eletromecânicas em sistemas de potência.
Este trabalho propõe uma nova metodologia de projeto de controladores para o amortecimento de oscilações eletromecânicas de baixa freqüência em sistemas de potência. Considerando a necessidade de se aumentar a robustez dos estabilizadores clássicos frente a variações nas condições de operação, este estudo analisou uma série de requisitos prát
Publicado em: 2002
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19. Modelo de sensibilidade de potencia para analise da estabilidade de tensão em sistemas de energia eletrica
This work presents two versions of a model based on power balance methodology for small signal voltage stability studies of a isolated system. The main characteristic of this model relies on the preservation of the system s structure. As a consequence, it is possible to compare the dynamic and static approaches of the problem. Test results for different gene
Publicado em: 1997
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20. Deletion analysis of the internal signal-anchor domain of the human asialoglycoprotein receptor H1.
The human asialoglycoprotein receptor H1 is a single-spanning membrane protein with the amino terminus facing the cytoplasm and the carboxy terminus exposed on the exoplasmic side of the plasma membrane. It has been shown earlier that the transmembrane segment, residues 38-65, functions as an internal signal directing protein synthesis to the endoplasmic ret
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21. The decline in human Alu retroposition was accompanied by an asymmetric decrease in SRP9/14 binding to dimeric Alu RNA and increased expression of small cytoplasmic Alu RNA.
Alu interspersed elements are inserted into the genome by a retroposition process that occurs via dimeric Alu RNA and causes genetic disorders in humans. Alu RNA is labile and can be diverted to a stable left monomer transcript known as small cytoplasmic Alu (scAlu) RNA by RNA 3' processing, although the relationship between Alu RNA stability, scAlu RNA prod
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22. Construction and genetic analysis of dicistronic polioviruses containing open reading frames for epitopes of human immunodeficiency virus type 1 gp120.
On the basis of previous studies of dicistronic (dc) polioviruses that carried two internal ribosomal entry sites (L. Alexander, H.-H. Lu, and E. Wimmer, Proc. Natl. Acad. Sci. USA 91:1406-1410, 1994; A. Molla, S. K. Jang, A. V. Paul, Q. Reuer, and E. Wimmer, Nature [London] 356:255-257, 1992), we have constructed a variety of dc polioviruses which express f
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23. Long-term performance of a hand held spirometer.
BACKGROUND: A study was undertaken to test the long term performance of a small hand held spirometer for self-administered serial spirometric testing. METHODS: Thirty turbine pocket spirometers (MicroMedical DiaryCard) were used in a clinical trial on 22 emphysematous patients with severe alpha 1-antitrypsin deficiency. The spirometers were able to store the
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24. Sequences from polyomavirus and simian virus 40 large T genes capable of immortalizing primary rat embryo fibroblasts.
We developed a procedure to evaluate quantitatively the capacity of subgenomic fragments from polyomavirus and simian virus 40 (SV40) to promote the establishment of primary cells in culture. The large T antigen from both of these viruses can immortalize primary rat embryo fibroblasts. Both antigens have amino-terminal domains that retain biological activity