Partial Discharges
Mostrando 1-12 de 27 artigos, teses e dissertações.
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1. Simulation of Current Pulses and Sound Waves Resulting from Partial Discharges in a Needle-Plane Geometry in Air
Abstract Partial discharges can occur in different types of electric equipment and cause progressive insulation deterioration, so there is interest in monitoring partial discharges for assessing the state of the isolation of an electric system and to predict failures. Techniques to detect partial discharges, such as detecting ultrasonic emission, have been p
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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2. Phosphorus and thermotolerant coliforms’ loads in Brazilian watersheds with limited data: considerations on the integrated analysis of water quality and quantity
RESUMO Análises integradas dos aspectos qualitativos e quantitativos de ambientes aquáticos robustecem a tomada de decisão, que se vincula ao gerenciamento dos recursos hídricos e à promoção dos serviços ecossistêmicos. Contudo, as possíveis vantagens desta integração ainda esbarram em aspectos básicos, como elevadas incertezas devido ao monito
RBRH. Publicado em: 31/01/2019
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3. A System Based on Artificial Neural Networks for Automatic Classification of Hydro-generator Stator Windings Partial Discharges
Abstract Partial discharge (PD) monitoring is widely used in rotating machines to evaluate the condition of stator winding insulation, but its practice on a large scale requires the development of intelligent systems that automatically process these measurement data. In this paper, it is proposed a methodology of automatic PD classification in hydro-generato
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-09
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4. Spectral Method for Localization of Multiple Partial Discharges in Dielectric Insulation of Hydro-Generator Coils: Simulation and Experimental Results
Abstract A methodology based on spectral analysis for localization of multiple partial discharges in dielectric region of hydro-generator coils is proposed. This pinpointing of multiple discharges aims to provide means for performing diagnosis of insulating regions of the coil. A numerical model of the structure was developed by using the finite-difference t
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2016-09
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5. Analysis and Comparison of Sensors for Measurements of Partial Discharges in Hydrogenerator Stator Windings
Abstract In order to measure electrical signals produced by partial discharges in hydrogenerators stator windings, capacitive couplers are regularly used. They are electrically connected to the windings and therefore, require undesired insulation intrusion. For avoiding such an intrusion, a microstrip directional coupler is used, which is experimentally and
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2015-12
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6. Optical detection system of partial discharges on insulator strings of high voltage transmission lines / Sistema de detecÃÃo Ãptica de descargas parciais em cadeias de isoladores de linhas de transmissÃo de alta tensÃo
Leakage current monitoring is frequently used to evaluate the degradation in the insulation capacity of insulator strings of overhead transmission lines, due to pollution. The pollutants accumulation over the surface of the insulators strings, together with humidity, lead to an increase in the current leak over the insulatorâs surface, in turn producing the
Publicado em: 2008
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7. Landau-Kleffner syndrome clinical, eletroencepholographic and psychosocial aspects : long-term follow-up / Sindrome de Landau Kleffner aspectos clinicos, eletrencefalograficos e psicossociais : estudo de seguimento a longo prazo
Purpose: Landau-Kleffner syndrome (LKS) is a rare entity characterized by epilepsy and aphasia. It occurs in previously normal children, usually between 3 and 7 years of age. The long-term outcome of the LKS is not completely clear. The aim of this study is to verify the long-term follow-up of a group of patients with LKS, focusing on clinical aspects, EEG,
Publicado em: 2008
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8. Modelagem endoscÃpica virtual do monitoramento de equipamentos elÃtricos de alta tensÃo
With the promulgation of the 10.847/2004 and 10.848/2004 Laws, the Brazilian Power Sector started adopting competitiveness as the main element for obtaining concessions in the electric power system transmission and generation sectors. In this sense, the power sector companies will have to strongly intensify the monitoring processes of the power system equipm
Publicado em: 2007
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9. UM SISTEMA DE DIAGNÓSTICO DE EQUIPAMENTOS ELÉTRICOS DE ALTA TENSÃO COM BASE NA OCORRÊNCIA DE DESCARGAS PARCIAIS / A DIAGNOSTICS SYSTEM OF HIGH VOLTAGE POWER APPARATUS BASED IN PARTIAL DISCHARGES OCURRENCE
High voltage (HV) power apparatus are fundamental parts in the industrial process. It is also well Known that electrical insulation systems are the parts that present more problems through the life cycle of an HV apparatus. The dielectric properties of materials are altered during operation time and for this reason they should be monitored. Among the main an
Publicado em: 2001
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10. ESTUDO SOBRE O ESTADO DO ISOLAMENTO DE MÁQUINAS ELÉTRICAS ROTATIVAS DE ALTA TENSÃO / A STUDY RELATED WITH THE ISOLATION CONDITION OF HIGH TENSION ROTATING ELECTRIAL MACHINES
O Monitoramento do Sistema de Isolamento em Máquinas Elétricas de Alta Tensão representa um avanço no que diz respeito ao planejamento operacional de uma indústria. Com posse de dados on-line referentes às condições apresentadas pelos isolamentos, as devidas precauções podem ser tomadas, evitando danos maiores. O trabalho apresentado tem como objet
Publicado em: 1997
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11. Displasias corticais associadas a epilepsia : delineamento de uma nova sindrome, revisão de conceitos localizacionais e proposta de uma nova classificação
Modemneuro:imagingtechniques current1y allows lin vivo I identification of cortical dysplastic lesions in patients previously thought to have cryptogenic epilepsies. These lesions constitute an heterogenous group of disorders from clinicall anatomical, histopathological, and pathogenetic standpoints. The fact that such heterogeneity is not readily realized o
Publicado em: 1996
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12. Restoration of function in external intercostal motoneurones of the cat following partial central deafferentation.
The activity of external intercostal motoneurones in the cat was studied under anaesthesia and paralysis before and after partial central deafferentation caused by single or double ipsilateral hemisections of the thoracic spinal cord. The normal efferent inspiratory discharges recorded from external intercostal nerve filaments caudal to the upper lesion were