Results 261 to 270 of about 24,218,867 (287)

Influence of space charges on the breakdown of oil-paper insulation

Conference on Electrical Insulation & Dielectric Phenomena — Annual Report 1967, 1967
It is a well-known fact that when some insulants under dc voltage are subjected to a polarity reversal, the breakdown immediately after the reversal may appear at a substantially lower voltage than the breakdown without polarity reversal. Since complete discharging of the sample does not occur after the polarity reversal, the voltage due to the charges
G. S. Eager, G. Bader, F. G. Garcia
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Characteristics of moisture diffusion in vegetable oil-paper insulation

IEEE Transactions on Dielectrics and Electrical Insulation, 2012
Vegetable insulating oils are fire-resistant and environment-friendly liquid dielectrics. The current paper presents an experiment system to simulate moisture diffusion in the insulation system consisting of vegetable insulating oil and insulation paper. The results show the coefficient of moisture diffusion in vegetable oil-paper insulation.
Jian Li, Zhaotao Zhang, Stanislaw Grzybowski, Yu Liu   +3 more
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Direct determination of moisture in solid oil-paper insulation

Conference Record of the 1998 IEEE International Symposium on Electrical Insulation (Cat. No.98CH36239), 2002
The life of oil-paper insulation depends critically on the moisture content in paper. At present no method is available for direct measurement of moisture in paper insulation in transformers. This paper summarizes the results from a project for development of a method for direct measurement of moisture in paper in oil-paper insulated electrical ...
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New Equivalent Circuit of Oil-Paper Insulation and Its Parameters Identification

2020 16th International Conference on Computational Intelligence and Security (CIS), 2020
In order to finding more perfect dielectric response function, the mixed polarization equivalent circuit model is proposed by combining interface polarization equivalent circuit model in oil paper insulation, which fit the actual relaxation process of oil paper insulation system. At the same time, to resolve complex computational problems of parameters
Dehua He, Ruliang Wang
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State Assessment of Oil-Paper Insulation Based on Fuzzy Rough Sets

2019 15th International Conference on Computational Intelligence and Security (CIS), 2019
Return voltage method (RVM) is effective method to valuate aging state of transformer insulation. However, it is difficult to accurately assess the insulation aging state by a single characteristic quantity. In this paper, the fuzzy rough sets combined with return voltage method is proposed to assess the oil paper insulation state of transformer and ...
Dehua He, Ruliang Wang
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Influence of proportion of vegetable insulating oil and mineral insulating oil on thermal aging of oil-paper insulation

2013 Annual Report Conference on Electrical Insulation and Dielectric Phenomena, 2013
Vegetable insulating oil shows good performance in electric, high anti-aging ability and environmental protection. Thus it is considered as a promising substitute for mineral insulating oil. In order to the wide spread application of vegetable oil in large power transformers, this paper presents accelerated aging experiments of oil-paper insulation ...
Baimei Wang, Jian Li, Junru Xiang, Bin Du   +3 more
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The velocity of drying of the already impregnated oil-paper insulation

Proceedings of 5th International Conference on Properties and Applications of Dielectric Materials, 2002
It is well known that the paper-oil insulation is so prepared, that the paper installed in the high voltage apparatus is first dried up with the influence of high vacuum and elevated temperature. Then, under vacuum the paper is impregnated with oil.
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Compatibility of tracer gases with oil/paper cable insulation

1983 EIC 6th Electrical/Electronical Insulation Conference, 1983
This paper describes the results of an investigation designed to evaluate the long-term compatibility of tracer gases with HPOF cable insulation in view of selecting one or several gases for the detection of leaks in underground cable networks. Accelerated aging was done on cable models with He, CF 4 , SF 6 , c-C 4 F 8 and N 2 gases dissolved in the ...
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State Assessment of Oil-Paper Insulation Based on Fuzzy Rough Sets

2016
Return voltage method (RVM) is a good method to study aging state of transformer insulation, but it is difficult to accurately assess the insulation aging state by a single characteristic quantity. In this paper, the fuzzy rough sets theory combined with RVM is proposed to assess the oil paper insulation state of transformer and construct the ...
De-Hua He, Jin-Ding Cai, Song Xie, Qing-Mei Zeng   +3 more
openaire   +2 more sources

Aging Assessment Model of Transformer Insulation Based on Furfural Indicator Under Different Oil/Pressboard Ratios and Oil Change

IEEE Transactions on Dielectrics and Electrical Insulation, 2021
Jiefeng Liu, Yiyi Zhang, Heng Zhang
exaly