Harmonic Estimation
Mostrando 1-12 de 12 artigos, teses e dissertações.
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1. Inteligência computacional aplicada a modelagem de cargas não-lineares e estimação de contribuição harmônica
A distorção harmônica, dentre outras formas de poluição na rede de sistemas de energia, é um importante problema para as concessionárias. De fato, o aumento do uso de dispositivos não-lineares na indústria resultou em um aumento direto da distorção harmônica nos sistemas elétricos de potência nos últimos anos. Com isso, a modelagem destas carg
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 29/02/2012
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2. Estimação de estados de distorções harmônicas em sistemas elétricos de potência utilizando estratégias evolutivas. / Power systems harmonic distortion state estimation using evolutionary strategy.
The aim of the present thesis is to develop a Harmonic Distortion State Estimation algorithm for Power Systems. Although the cost of Power Quality Meters has decreased for a while now, it is still not practicable the use of one meter for each real system bus. This demands a Harmonic Distortion State Estimation (HDSE) algorithm to find the harmonic components
Publicado em: 2008
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3. 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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4. ESTIMAÇÃO DE HARMÔNICOS/INTER-HARMÔNICOS: UMA ABORDAGEM MULTITAXA
This dissertation discusses parameter estimation of harmonics/inter-harmonics of electrical signals under time-varying conditions. Two new suitable approaches for processing this kind of signals are proposed. The first one is based on phase error of DFT (Discrete Fourier Transform) result, occurring due to the frequency deviation of input signal. This method
Publicado em: 2008
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5. MÃtodos de sincronizaÃÃo de conversores em sistemas de geraÃÃo distribuÃda / Converter synchronization methods for distributed generators systems
The use of frequency converters DC/AC to integrate renewable energy as distributed generation is becoming more common. In such applications, the synchronization with the voltage vector is fundamental to control the converters, particularly considering the new requirements on Low Voltage Ride Through demanded from the distributed generation. This work propose
Publicado em: 2008
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6. A Contribution to the Estimation of Indicators of the Operational State of Insolated Power Cables with Water Trees / Uma contribuição à estimativa de indicadores de desempenho do estado operacional de cabos isolados sob a ação das arborescências
Distinct matters related to power quality challenges represent areas of growing interest for the electric engineering community. By considering the subject of power supply with quality and reliability, the continuity of the supply appears as a very important task to be fulfilled. As a matter of fact, the occurrence of failures in components and installations
Publicado em: 2008
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7. Comparison of expected progeny difference estimatives by three methodologies in Nellore beef cattle / Comparação de estimativas de diferenças esperadas de progênie por três metodologias em touros da raça Nelore
The strong competition in beef market imposed an actual trend of searching for quality in beef production systems, trying to attend the consumersdemand. Due to the necessity of increasing productivity, animal breeding programs have been utilized to increase cattle efficiency, offering more profitability to the production system. The present study was carried
Publicado em: 2007
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8. Non linear signal analysis applied to friction force identification in tribological tests / Identificação da força de atrito através de análise de sinais não lineares em ensaios tribológicos
When the surfaces of two elastic bodies present relative motions under certain amount of contact pressure the mechanical system can be instable. Experiments conducted on elastic bodies under friction forces shown that the dynamical system is self-excited by the non-linear behavior of frictional forces. The main objectives of this thesis are the study of the
Publicado em: 2005
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9. Estudo e Aperfeiçoamento do Vocoder de Transformada Senoidal
The basic sinusoidal analysis/synthesis system is presented and recent parameters codification techniques are studied. In addition, new methods for improving the speech quality of Sinusoidal Transform Vocoders at 2,4 and 4,8 Kbps are presented. One of them is a refinement in the pitch estimation, since pitch accuracy is essential for the efficiency of the ha
Publicado em: 2004
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10. A new robotic drive joint friction compensation mechanism using neural networks
The knowledge of realistic dynamic models to robotic actuators would be of great aid in the synthesis of control laws to robot manipulators, mainly in cases of great precision robotic or even for manipulators with flexible links. In this paper we present a training scheme and propose a structure of neural network (NN) to learn the friction torque of a geared
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2003-04
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11. ESTIMAÇÃO EM TEMPO REAL DE SENÓIDES HARMÔNICAS POR DECOMPOSIÇÃO EM SUB-BANDAS / REAL TIME HARMONIC SINE WAVE ESTIMATION BY SUB-BAND DECOMPOSITION
A medição da qualidade de energia é um aspecto cada vez mais importante com o avanço tecnológico. Um destes aspectos é a estimação dos harmônicos em sinais de potência. Este trabalho, apresenta um algoritmo para obter, simultaneamente, os valores reais de freqüência, amplitude e fase de cada componente do sinal, baseados em valores distorcidos or
Publicado em: 1999
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12. MÉTODO DE AMORTECIMENTO DIRETO COM TRATAMENTO DA SAZONALIDADE ATRAVÉS DO MÉTODO HARMÔNICO DE HARRISON / DIRECT EXPONENTIAL SMOOTHING METHOD INCORPORATING SEASONAL COMPONENT MODELLED BY HARRISON HARMONIC APPROACH
The method of exponential smoothing, although originally propesed during the 60´s, still continues in use up to today. In this thesis we present a new forecasting method for time series / with and/or without seasonality, applying the theory of exponential smoothing and harmonic analysis. It is assume that the series is composed of secular trend (constant, l
Publicado em: 1985