Power Systems Protection
Mostrando 13-24 de 50 artigos, teses e dissertações.
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13. Desempenho de Linhas de Distribuição frente a Descargas Atmosféricas:: estudo e Implementação do Guia IEEE Std 1410
Lightning is one of the most important sources of disturbances in distribution systems that can cause permanent or momentary interruptions. The growing concern regarding power quality has created great interest in the interaction of lightning with power systems and an improved protection against its effects on distribution lines. Studies indicate that, in Br
Publicado em: 2009
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14. IEC-61850: interoperability and interchangeability between supervision, control and protection equipment using data communication networks / IEC-61850: interoperabilidade e intercambialidade entre equipamentos de supervisão, controle e proteção através das redes de comunicação de dados
Data communication has always been considered as a critical factor in real time operation of electric power systems. This is due to the need for fast and accurate decisions at different locations, from power generation to the user interfaces. With the digital technology, measurement, signals and commands are encrypted into data packets that travels on the su
Publicado em: 2009
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15. ELECTRIC DISTRIBUTION POWER SYSTEMS RELIABILITY OPTIMIZATION: An Approach Considering the Selection and Allocation of Protection and Switching Devices / OTIMIZAÇÃO DA CONFIABILIDADE DE SISTEMAS DE DISTRIBUIÇÃO DE ENERGIA ELÉTRICA: Uma Abordagem Considerando a Seleção e Alocação de Dispositivos de Proteção e Manobras
One of the main goals of the electric utilities is to provide energy to its customers in a reliable and low cost way. Traditionally, the electricity sector regulatory commissions impose continuity targets, which must be carried out, to avoid great penalties. For many years, the electric utilities have adopted the practice of allowing the increment of tempora
Publicado em: 2009
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16. Analise dos sistemas de proteção e controle de instalações industriais com geradores sincronos durante operação ilhada / Protection and control systems analysis of industrial plants with synchronous generators during islanded operation
Modern industrial systems are very sophisticated installations with a high number of automatic processes and capability of isolated (islanded) operation after contingences by using onsite generators composed mainly by synchronous machines and steam turbines. Such installations, in the presence of generators, are generically called autoproducers. Since many o
Publicado em: 2009
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17. Using a multi-agent system in communication networks for an adaptive digital distance protection system / Utilização de um sistema multi-agentes em redes de comunicação para a proteção digital de distância adaptativa
This research presents the development of an adaptive digital distance protection system by a multi-agent system (MAS). This MAS will work in a distributed way, with expert entities (agents) inserted in specific places and acting efficiently in the solution of local problems. With the application of the MAS, the distance relays will have desirable characteri
Publicado em: 2009
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18. Use of Wavelet Transforms to Detect Abnormal Frequency Variation in Distributed Generation Systems / Utilização da transformada de Wavelet para detectar variações anormais de freqüência em sistemas de geração distribuída
This dissertation focuses the importance of registering eventual frequency variations in Electric Power System which may cross the established limits for normal operation. These can cause serious problems in the operation of sensitive equipments connected to the electric grid, such as the turbo-generators employed in thermoelectric plants. For power system f
Publicado em: 2009
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19. The peculiarities of health systems in Mercosurs member countries: prospects for a regional integration / As peculiaridades dos sistemas de saúde dos países membros do Mercosul: perspectivas para a integração regional
Abstract This qualitative study, based on the comparative-descriptive and analytical-descriptive methods, identifies and historically describes the harmonization process of the health care systems of Mercosurs member countriesArgentina, Brazil, Paraguay and Uruguayin line with the regional integration process under way. It focuses on understanding (i) the hi
Publicado em: 2009
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20. Localização de defeitos em alimentadores primários subterrâneos : formulação estendida baseada na impedância aparente
O presente trabalho apresenta uma abordagem estendida para o diagnóstico de faltas em sistemas subterrâneos de distribuição de energia. O esquema proposto desenvolve modificações às técnicas de localização de defeitos em sistemas de distribuição aéreos baseadas no cálculo da impedância aparente, adaptando-as para a aplicação em alimentadores
Publicado em: 2009
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21. Evaluation of boom hydraulic sprayers in the region of Uberlândia-MG / Avaliação de pulverizadores hidráulicos de barra na região de Uberlândia-MG
Any and every manner of pesticide application represents environmental risks, which must be minimized by the use of proper knowledge and technology, assuring a sustainable food production. Often, great importance is given to the pesticide and little to the application technique. The identification of the conservation state and mode of use of the sprayers in
Publicado em: 2009
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22. Algoritmos genéticos aplicados à proteção e estimação de harmônicos em sistemas elétricos de potência / Genetic algorithms applied to protection and harmonic estimation in electric power systems
The aim of electric power systems is to generate electricity and to deliver it continuously to the end-user in an acceptable standard. Therefore, different applications using genetic algorithms (GAs) to solve electric power system problems are presented in this work. Harmonic estimation, frequency relays and distance protection are the subjects investigated
Publicado em: 2008
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23. ALGORITMOS HEURÍSTICOS DE OTIMIZAÇÃO DA PROTEÇÃO E MANOBRA EM REDES DE DISTRIBUIÇÃO DE ENERGIA / RELIABILITY HEURISTIC ALGORITHMS FOR PROTECTION AND MANEUVERING DEVICES DISTRIBUTION NETWORKS
The new regulations of the electricity sector have requested from the power utilities great performance efficiency on their distribution systems, requiring more rigorous quality and continuity energy levels. In Brazil, the privatization of the power utility companies has been allowing the adoption of new planning and operation policies, that necessarily cons
Publicado em: 2008
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24. 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