Power System Signal Analysis
Mostrando 13-24 de 39 artigos, teses e dissertações.
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13. 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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14. Virtual instrumentation applied to electrical engineering education. / Instrumentação virtual aplicada ao ensino experimental de engenharia elétrica.
The proposal of this work is to present some potential applications of the software LabVIEW, from National Instruments, associated with data acquisition hardware, applied to experiments in the Electric Energy Systems area as a tool to support the presential education. This dissertation shows the developing of an experience in a electric energy system laborat
Publicado em: 2007
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15. Tool for modeling communication systems. / Ferramenta para modelagem de sistemas de comunicação.
This work presents a tool for the simulation of Communication Systems using macromodels for each block used. The tool is based on behavioral models of Radio Frequency (RF) blocks, which minimize cost, simulation time and allows a fast determination of problems in the early phases of the design of a Wireless Communication System. The development of blocks lik
Publicado em: 2007
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16. O homem-placa e o pixman: uma análise de duas ferramentas publicitárias que utilizam o corpo como suporte midiático / The placardman and the pixman: a study on two marketing tools which make use of the human body as media aid
The present research is about the placardman and the pixman, two marketing tools which make use of the human body as media aid. The sandwichmen men, rarely women walk around the streets of commercial centers in big cities draped in two wooden placards, announcing several products and services such as the selling of gold or the buying of subway and employee m
Publicado em: 2007
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17. Projeto de novos sistemas-wavelet com aplicaÃÃes na anÃlise de sinais do sistema elÃtrico / Design of new wavelet systems with applications in power system signal analysis
The wavelet transform equipped with the multiresolution analysis has been offered as an efficient tool in the investigation of non stationary signals derived from a plenty of areas. The development of new âbasisâ so as to implement such techniques has the aim of enlarging the span of suitable choices for a particular purpose. This thesis introduces new fam
Publicado em: 2006
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18. Sistema de controle e automação aplicável a secadores em camada fina utilizando-se instrumentos digitais endereçáveis / Automation and control system applicable to thin-layer grain dryer by using digital addressable instruments
Many grain-dryers models with different configurations and applications are encountered worldwide. Among those a thin-layer dryer makes it possible to perform detailed analysis of the drying process. With the results from this analysis results, the drying curves can be modeled and the deep bad grain drying process can be predicted. The thin layer grain dryer
Publicado em: 2006
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19. Uma proposta de controle de paralelismo de inversores com a rede elétrica utilizando-se a técnica de realimentação de fase
Este trabalho apresenta um controlador de fluxos de potência ativa e reativa aplicado ao paralelismo de um inversor com a rede elétrica. Uma malha adicional de controle é inserida a um controlador convencional, o qual é baseado nas curvas características de potência ativa versus freqüência e potência reativa versus tensão. Essa malha utiliza a real
Publicado em: 2006
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20. 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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21. Desenvolvimento de um sistema de imageamento usando a tomografia por coerÃncia Ãptica no domÃnio temporal e de Fourier
In this dissertation, we describe the basic theory and details of the implementation of three experimental optical coherence tomography systems, two in the time domain and one in the spectral (Fourier) domain. Optical coherence tomography (OCT) is a non invasive optical imaging method, capable of producing cross-sectional images of materials and biological t
Publicado em: 2006
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22. 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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23. Localization of lacks in average lines and high tension using efficient codification / Localização de faltas em linhas de média e alta tensão utilizando codificação eficiente
Signal processing techniques have been used to estimate fault location in medium and high voltage transmission lines, taking into account information obtained from travelling waves, generated at the moment of the fault. The main problem is to find the second reverse travelling wave that reflects on the fault point and returns to the measurement point from di
Publicado em: 2005
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24. Avaliação da Relação entre Qualidade Perceptual da Fala e Taxa de Acerto de Sistemas de Reconhecimento de Fala em Ambientes Ruidosos
The goal of this work is to evaluate the distortion of the noisy speech signal being after enhanced by noise-reduction algorithms. This is performed by comparison of word accuracy (%) of a standardized Automatic Speech Recognition (ASR) system and objective measures of perceptual speech quality (PESQ-MOS score), obtained after applying noise-reduction method
Publicado em: 2005