Transformers
Mostrando 1-12 de 113 artigos, teses e dissertações.
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1. Technical Losses Reduction in Underground Reticulated Distribution Systems using Artificial Neural Networks and Smart Grid Features
ABSTRACT This work presents the methodology, development and testing of an autonomous system, based on Artificial Neural Networks (ANN), for the reduction of technical losses in reticulated underground systems through the optimal control of the capacitor banks (CBs) present in the grid. The proposed methodology includes Smart Grid features, including practic
Braz. arch. biol. technol.. Publicado em: 22/10/2018
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2. Broadband Equal Power Divider
Abstract This paper presents the design of broadband two way equal power divider in microstrip medium with defected ground structure suitable for broadband communication systems. Quarter wave broadside coupled lines are used in the place of conventional transformers widely used in the popular Wilkinson power dividers. The proposed power divider structure tak
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-04
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3. Materiales ferromagnéticos: “¿Cómo es eso que el vector H se da vuelta?”
One of the major difficulties that students find in the basic subjects of Electricity and Magnetism is the understanding of the magnetic properties of matter. In particular, the determination of the directions of magnetic vectors in simple devices constructed with ferromagnetic materials such as magnets, transformers and electromagnets. The confusion is comp
Rev. Bras. Ensino Fís.. Publicado em: 19/01/2017
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4. Correlation between stabilizer consumption and degree of polymerization of thermally upgraded paper aged in insulating natural ester and insulating mineral oil
Abstract Insulating paper holds significant importance in the insulation system of power transformers, and thus, its degradation is the subject of many studies. A successful evaluation of the degradation rate of such paper contributes to reducing downtime and avoiding equipment failure. In this work, samples of thermally upgraded paper were thermally aged in
Polímeros. Publicado em: 04/03/2016
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5. SIMULATION OF THERMAL DECOMPOSITION OF MINERAL INSULATING OIL
Abstract Dissolved gas analysis (DGA) has been applied for decades as the main predictive maintenance technique for diagnosing incipient faults in power transformers since the decomposition of the mineral insulating oil (MIO) produces gases that remain dissolved in the liquid phase. Nevertheless, the most known diagnostic methods are based on findings of sim
Braz. J. Chem. Eng.. Publicado em: 2015-09
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6. AVALIAÇÃO DAS NORMAS DE ENSAIO APLICADAS NA QUANTIFICAÇÃO DE PCBs EM ÓLEO ISOLANTE
Polychlorinated biphenyls (PCBs) were widely used between 1940 and 1970 as an insulating fluid for transformers and capacitors. However, they are bioaccumulative and potentially carcinogenic and, according to the 2001 Stockholm Convention, must be eliminated by 2025. In Brazil, they have been gradually eliminated but contaminated equipment remains. The Brazi
Quím. Nova. Publicado em: 2015-05
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7. DEVELOPMENT OF INSULATING MAGNETIC OIL FOR TRANSFORMERS
The Centrais Elétricas do Norte do Brasil AS – Eletronorte, as well as other companies in the world energy sector, have problems of loss of the performance by excessive heat and even accidents with their transformers. The maintenance and accidents impact of energy supply, generating profit and more expensive insurance premiums. The transformers are essent
Publicado em: 20/07/2014
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8. Avaliação de diferentes métodos para a determinação de cobre em óleo mineral isolante por espectrometria de absorção atômica com forno de grafite
This aim of this work was to compare two methods for copper determination in insulating oils from power transformers by GFAAS. The first method was extraction induced by emulsion breaking, which determined the preconcentration of copper in an aqueous solution and exhibited a limit of quantification of 0.27 µg L-1. Also, a second method based on the direct i
Quím. Nova. Publicado em: 2014-06
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9. Wound rotor doubly fed induction machine with radial rotary transformer
This paper shows a wound rotor doubly fed induction machine in which the typical brushes and slip-rings are substituted by rotary transformers. The advantages of rotary transformer usage, the doubly fed induction machine operation and the dimensioning of a radial rotary transformer are the main aspects presented in this study. The use of analytical equations
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2013-12
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10. HYBRID SYSTEM FOR RULE EXTRACTION APPLIED TO DIAGNOSIS OF POWER TRANSFORMERS / SISTEMA HÍBRIDO DE EXTRAÇÃO DE REGRAS APLICADO A DIAGNÓSTICO DE TRANSFORMADORES
Este trabalho tem como objetivo construir um classificador baseado em regras de inferência fuzzy, as quais são extraídas a partir de máquinas de vetor suporte (SVMs) e ajustadas com o auxílio de um algoritmo genético. O classificador construído visa a diagnosticar transformadores de potência. As SVMs são sistemas de aprendizado baseados na teoria do
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 10/09/2012
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11. DIAGNOSIS OF FAULTS IN POWER TRANSFORMERS USING SEMICONDUCTOR GAS SENSORS. / DIAGNÓSTICO DE FALHAS EM TRANSFORMADORES DE POTÊNCIA UTILIZANDO SENSORES DE GAS SEMICONDUTORES.
Esta dissertação introduz o estudo do uso de uma matriz de sensores de gases de dióxido de estanho na detecção de falhas em transformadores de potência, através dos gases dissolvidos no óleo. O objetivo desta pesquisa é analisar os dados obtidos pelos sensores de gás, utilizando algumas técnicas de reconhecimento de padrão, e desta forma, verific
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 30/08/2012
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12. Algoritmo híbrido e inteligente para o diagnóstico das condições operativas de transformadores de potência no contexto da qualidade da energia elétrica / Hybrid intelligent algorithm for the diagnosis of operating conditions of power transformers in the context of power quality
This research aimed to develop an algorithm able to diagnose the operating conditions of power transformers. The variables considered to classify the presented conditions were the normally used by differential protection logic, i.e., the differential current and the harmonic content in the signals in analysis. Moreover, the relationship between some phenomen
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 12/07/2012