Spelling suggestions: "subject:"[een] PARTIAL DISCHARGES"" "subject:"[enn] PARTIAL DISCHARGES""
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Partial Discharge Activity in Electrical Insulation for High Temperature Superconducting (HTS) CablesOkubo, H., Kojima, H., Endo, F., Sahara, K., Yamaguchi, R., Hayakawa, N. 06 1900 (has links)
No description available.
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Charge accumulation effects on time transition of partial discharge activity at GIS spacer defectsOkubo, Hitoshi, Endo, Fumihiro, Hayakawa, Naoki, Kojima, Hiroki, Nishizawa, Kanako, Mansour, Diaa-Eldin A 02 1900 (has links)
No description available.
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Partial discharge characteristics of inverter-fed motor coil samples under ac and surge voltage conditionsHayakawa, Naoki, Okubo, Hitoshi 01 1900 (has links)
No description available.
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Time Variation of Partial Discharge Activity Leading to Breakdown of Magnet Wire under Repetitive Surge Voltage ApplicationHayakawa, Naoki, Inano, Hiroshi, Nakamura, Yusuke, Okubo, Hitoshi 12 1900 (has links)
No description available.
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Partial Discharges and Associated Mechanisms for Micro Gap Delamination at Epoxy Spacer in GISOkubo, Hitoshi, Endo, Fumihiro, Hayakawa, Naoki, Kojima, Hiroki, Mansour, Diaa-Eldin A 06 1900 (has links)
No description available.
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A novel technique for partial discharge and breakdown investigation based on current pulse waveform analysisOkubo, Hitoshi, Hayakawa, Naoki 08 1900 (has links)
No description available.
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Thermal Degradation In Composite Insulation Due To Corona DischargesJanuary 2010 (has links)
abstract: Composite insulators on overhead lines are frequently subjected to corona discharges due to increased electric field intensities under various conditions. These discharges can cause localized heating on the surface and affect the hydrophobicity of the insulator. A study has been undertaken to quantify and evaluate the thermal degradation that composite insulation is subjected to from corona discharges. This has been conducted primarily at the power frequency (60 Hz) and at the low frequency range (37 kHz). Point to plane corona discharge experiments have been performed in the laboratory at both the frequencies and varying levels of thermal degradation has been observed. The amplitude and the frequency of current spikes have been recorded at different voltage levels. A temperature model based on the amplitude and the frequency of current data has been formulated to calculate the maximum temperature attained due to these discharges. Visual thermal degradation has been found to set in at a low frequency range while there is no visual degradation observed at power frequency even when exposed to discharges for relatively much longer periods of time. However, microscopic experiments have been conducted which revealed degradation on the surface at 60 Hz. It has also been found that temperatures in excess of 300 Celsius have been obtained at 37 kHz. This corroborates the thermo gravimetric analysis data that proves thermal degradation in silicone rubber samples at temperatures greater than 300 Celsius. Using the above model, the maximum temperature rise can be evaluated due to discharges occurring on high voltage insulation. This model has also been used to calculate the temperature rise on medium voltage distribution equipment such as composite bushings and stand-off plugs. The samples were subjected to standard partial discharge tests and the corresponding discharge magnitudes have been recorded. The samples passed the tests and the corresponding temperatures plotted have been found to be within thermal limits of the respective insulation used on the samples. The experimental results concur with the theoretical model. A knowledge of the maximum temperatures attained due to these discharges can help in design of insulation with better thermal properties. / Dissertation/Thesis / M.S. Electrical Engineering 2010
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Etude de l'origine des décharges partielles sur les substrats céramiques enrobés / Study of the origin of partial discharges on ceramic coated substratesVu, Thi Anh Tho 13 July 2011 (has links)
Ce travail concerne l'étude du phénomène de décharges partielles dans les matériaux isolants utilisés en électronique de puissance. En utilisant des méthodes de détection électrique et optique, le mécanisme de décharge partielle sur des substrats d'AlN dans l'huile silicone a été étudié sur un grand nombre d'échantillons. La variation de la nature du substrat (AlN, Al2O3 et composite verre/époxy) et du matériau d'encapsulation (huile silicone, huile de colza, huile minérale de transformateur, liquide d'imprégnant du condensateur Jarylec et Ugilec) met en évidence l'origine des décharges partielles de l'ensemble substrat – encapsulant. Les décharges partielles sur les substrats céramiques frittés ne dépendent pas du passivant, et se produisent dans le volume du substrat. L'évolution temporelle de la lumière émise dans les liquides en configuration pointe – plan et sur le substrat dans différents liquides montre que l'émission de lumière est un phénomène très complexe influencé par de nombreux paramètres : électroluminescence du solide, de l'encapsulant, décharges partielles, absorption des matériaux. Le phénomène d'électroluminescence du liquide est activé par une illumination extérieure. Les mesures de spectroscopie diélectrique haute tension n'apportent pas d'information supplémentaire sur le phénomène de décharges partielles, car les pertes correspondantes sont très faibles. / This work concerns the study of partial discharge phenomena on insulating materials used in power electronics. Using electrical and optical detection methods, the mechanism of partial discharges on AlN substrates in silicon oil is studied with a large number of samples. Changing the nature of substrates (AlN, and Al2O3 composite glass/epoxy) and of encapsulating materials (silicone oil, rapeseed oil, mineral transformer oil, capacitor impregnating liquids Jarylec and Ugilec) provides a number of conclusions about the origin of partial discharges on embedded substrates. Partial discharges on sintered ceramic substrates do not depend on the encapsulating material nature, but on the nature of the substrates themselves. The temporal evolution of light emitted by the liquid in a point - plane configuration, and on embedded substrates shows that the light during emission is a very complex phenomenon influenced by many parameters: electroluminescence of the solid, of the encapsulating material, partial discharges, and light absorption of materials. The electroluminescence of the liquid is activated by external light. Measurements of high voltage dielectric spectroscopy are also performed, but no additional information on partial discharges is obtained since corresponding losses are very low.
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Optimalizace částečných výbojů UG 500R a UG550 pro napěťovou hladinu 17,5 kV / Optimization of partial discharges UG500R and UG550 for 17.5 kV voltage levelBajánek, Tomáš January 2013 (has links)
Master’s thesis deals with the optimization of partial discharges in switchgears ABB UniGear 500R and ABB UniGear 550 for 17,5 kV voltage level. It contains a description of the measurement method of partial discharges in metal enclosed medium voltage switchgears, analysis of the places where it may lead to formation of partial discharges and project of optimization of partial discharges in switchgears ABB UniGear 500R and ABB UniGear 550 for 17,5 kV voltage level.
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On-line partial discharges detection in conversion systems used in aeronautics / Détection on-line des décharges partielles dans des systèmes de conversion utilisés en aéronautiqueCella, Benjamin 02 December 2015 (has links)
Le concept de l'avion plus électrique a conduit les industriels à focaliser une partie de leurs efforts sur les risques liés à l'utilisation de la haute tension dans un environnement sévère (Basse pression, large plage de température et d'humidité …). Les risques associés sont l'existence et le développement de décharges partielles conduisant à terme à la défaillance du système dans lequel, elles se produisent. Considérant cette problématique, le groupe Liebherr Elektronik GmbH, en collaboration avec le laboratoire Laplace, a lancé l'étude d'une méthode permettant de détecter les décharges partielles dans des convertisseurs destinés à des applications aéronautiques. Ce sont les résultats de ce travail qui font l'objet de cette thèse. La première partie fait état des connaissances actuelles sur les décharges partielles, de leur nature physique aux méthodes de détection utilisées. Dans la seconde partie, trois phases de mesures validant l'efficacité de la méthode étudiée sont présentées et leurs résultats sont discutés. Enfin, dans une troisième partie, les conclusions de nos travaux et leurs perspectives sont présentées. / The more electrical airplane concept led industrial companies to focus a part of their efforts on risks linked to the use of high voltage in a severe environment (Low pressure, wide range of temperature and humidity …). Associated risks are the existence and the growing of partial discharges ultimately leading to the breakdown of the system in which they occur. Considering this problematic, the Liebherr Elektronik GmbH group, in collaboration with the Laplace laboratory, launched the study of a method allowing partial discharges detection in converters intended to be used in aeronautical applications. The results of this work are the subject of this thesis. The first part brings the status of the current knowledge about partial discharges from their physical nature to the detection methods which are used. In the second part, three measurement phases assessing the efficiency of the studied method are introduced and their results discussed. Finally, in the third part, the conclusionsof our works and their perspectives are presented.
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