Protection Of Transmission Lines
Mostrando 1-12 de 12 artigos, teses e dissertações.
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1. ESTIMAÇÃO DE FASORES NA PRESENÇA DE HARMÔNICOS, DECAIMENTO CC EXPONENCIAL E INTER-HARMÔNICOS EXPONENCIALMENTE AMORTECIDOS
This thesis presents the proposition of two novel methods in the field of phasor estimation. The first proposes to estimate the phasor of the fundamental component in the presence of harmonics and exponential decaying DC. This methodology is based on the application of filters DFT (Discrete Fourier Transform) and some methods of signal processing such as win
Publicado em: 2010
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2. Classificação e localização de faltas em linhas de transmissão usando diferentes arquiteturas de redes neurais artificiais. / Classification and location faults in transmission lines, using different artificial neural networks architectures.
This work presents the development of algorithms for determination of the estimate of the distance of occurrence of fault in a high voltage transmission line, in relation to a local terminal, and also the classification of the fault type, using techniques based on artificial neural networks. The tests and the validation of the proposed algorithms are made us
Publicado em: 2008
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3. InteraÃÃo transitÃria entre transformadores de potencial capacitivos e linhas de transmissÃo: uma contribuiÃÃo para minimizar falhas
Coupling capacitor voltage transformers (CCVT) are widely used in power systems for monitoring, protection relays and control aplications. Failure of this equipment may cause unexpected outages of transmission lines (TL), which may result in severe penalties as imposed by the regulatory agency of the government. This fact requires speeding maintenance proced
Publicado em: 2008
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4. Frequency estimation in power system through adaptive filtering / Estimação da freqüência em sistemas elétricos de potência através de filtragem adaptativa
This work presents a method for frequency estimation in power systems using adaptive filters based in the algorithm of least mean square (LMS). The analysis of the power system is made through the conversion of the three-phase voltages in a complex signal with the application of alfabetatransform, whose complex form was directed to the algorithm of adaptive
Publicado em: 2007
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5. Simulação computacional de descargas atmosfericas em estruturas de proteção visando analises de compatibilidade eletromagnetica
This work presents the study of protection against lightning through current transitory coniputational simulation and electromagnetic field results. The development of a new ana1ytical expression of calculation for the electromagnetic field was necessary (in Cartesian coordinates) due to the generality of the possible configurations of a structure. The proce
Publicado em: 2000
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6. Calculos de curtos-circuitos para estudo e analises da proteção de sistemas eletricos
This work describes the implementation of a software for short circuit calculations. Its objective is to facilitate the analysis and studies of electric systems protection. The main characteristics of the program consists: System pre fault state determination including shunt elements in the short circuit computation; parallel transmission lines mutual coupli
Publicado em: 1998
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7. Simulação numerica da interação raio-sistemas de proteção em treliças e do campo eletrico gerado
A numerical simulator of the lightning protection system of structures has been developed. The simulator predicts the current distribution on the guard cables and the assotiated electromagnetic fields. The calculations are done in the time domain. In this work, the protective structure is assumed to be composed of an interconnection of transmission lines. Th
Publicado em: 1993
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8. ANALYSIS OF THE PERFORMANCE OF PROTECTION SCHEMES IN ELECTRIC ENERGY EXTRA HIGH VOLTAGE TRANSMISSION SYSTEMS WITH SERIES COMPENSATION / ANÁLISE DO DESEMPENHO DE ESQUEMAS DE PROTEÇÃO EM SISTEMAS DE TRANSMISSÃO DE EXTRA ALTA TENSÃO DOTADOS DE COMPENSAÇÃO SÉRIE
The Constant growth of the demand for electrical energy in Brazil is leading to an increased use of the country¿s vast hydro potencial. The great size of the hydroelectric plants being planned for the near future, as well as their distance from the main load centers, will make it necessary to transmit vast amounts of power over long EHV lines. The electrica
Publicado em: 1974
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9. Vaccination with the ML0276 Antigen Reduces Local Inflammation but Not Bacterial Burden during Experimental Mycobacterium leprae Infection▿
Leprosy elimination has been a goal of the WHO for the past 15 years. Widespread BCG vaccination and multidrug therapy have dramatically reduced worldwide leprosy prevalence, but new case detection rates have remained relatively constant. These data suggest that additional control strategies, such as a subunit vaccine, are required to block transmission and
American Society for Microbiology (ASM).
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10. Expression of the human beta-amyloid precursor protein gene from a yeast artificial chromosome in transgenic mice.
One hallmark of Alzheimer disease is the formation in the brain of amyloid plaques containing a small peptide derived from the beta-amyloid precursor protein (APP). The APP gene exhibits a complex pattern of expression in peripheral tissues and in the brain. The entire human APP gene was introduced into embryonic stem (ES) cells by co-lipofection of a 650-kb
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11. Glycoprotein gp50-negative pseudorabies virus: a novel approach toward a nonspreading live herpesvirus vaccine.
Essential herpesvirus glycoproteins are involved in membrane fusion processes during infection, e.g., viral penetration and direct cell-to-cell transmission. We previously showed that the gD-homologous glycoprotein gp50 of pseudorabies virus (PrV) is essential for virus entry into target cells but proved to be dispensable for direct viral cell-to-cell spread
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12. A chimeric human immunodeficiency virus type 1 (HIV-1) minimal Rev response element-ribozyme molecule exhibits dual antiviral function and inhibits cell-cell transmission of HIV-1.
We have previously shown that hairpin ribozymes targeting the human immunodeficiency virus (HIV) genome can effectively inhibit virus replication in a variety of primary and cultured hematopoietic cells. To further increase antiviral potency and minimize the chance of viral resistance, we have now cloned the stem-loop II sequences of the HIV type 1 Rev respo