• Proceedings of the KIEE Conference
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• 2005.07e
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• pp.97-99
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• 2005

현장에서 사용중 고압전선에 고장이 발생한 6.6kV 건식변압기 고장의 원인분석을 위하여 설계와 제조방식이 동일하고 사용기간이 비슷한 건식변압기에 대한 전기적 열적 시험을 실시하였다. 전기적 시험으로서는 교류 및 충격 내전압시험, 부분방전시험을 실시하였고 열적시험으로는 단락법을 사용하여 온도를 상승시켰으며, 내부 및 외부권선표면의 온도분포와 열화상에 의한 온도분포를 측정하였다. 시험결과 부분방전특성이 기준치에 비하여 높게 나타났으며, 권선온도분포는 사용한계온도이하인 것으로 분석되었다.

• Proceedings of the KIEE Conference
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• 2005.11c
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• pp.93-95
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• 2005

건식변압기는 난연성 변압기로서 옥내나 선박과 같은 화재의 위험성이 있는 곳에 주로 사용된다. 본 연구에서는 삼상 건식변압기의 온도분포특성을 설명하였다. 부하율에 따라 온도분포특성시험을 실시하였으며, 온도센서와 열화상카메라를 이용하여 변압기의 온도를 측정하였다. 분석결과 온도는 두 권선이 인접한 곳에서 가장 크게 나타났다.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2007.11a
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• pp.170-170
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• 2007

• Transactions of the Korean hydrogen and new energy society
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• v.31 no.2
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• pp.194-201
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• 2020

Recently, Type 2 high-pressure hydrogen storage tank is studied due to fast defect detection, easy manufacturing, and cost efficiency. Moreover, the dry winding a high-strength metal wire will make increased economic efficiency compare with the wet winding method and the carbon/glass fiber winding method. In this study, a theoretical study on the dry winding of a Type 2 high pressure hydrogen tank using a metal wire was done, and the equations of the total stress on the aligned and the staggered winding for the hoop winding were derived, and the following results were obtained by using these equations. As the diameter of the metal wire, the number of winding layers, and the outer diameter of the liner increase, the maximum stress decreases, but the difference between the maximum stress occurring in the aligned winding and the staggered winding increases. As the pressure increases, the thickness of the winding layer increases, but as the strength of the metal wire increases, the thickness of the winding layer decreases. In addition, regardless of the strength of the metal wire, the thickness of the winding layer of the staggered winding was about 13.4% thinner than that of the aligned winding.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.511-517
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• 2016

Current oil-type potential transformers for trains are filled with insulating oil, which could have problems like explosions due to rising inner pressure during train operation. Therefore, mold and dry-type potential transformers are being developed to prevent explosions. One problem in manufacturing mold-type transformers is preventing void formation around the coiled core inside the mold during epoxy filling, which could cause an electrical spark. Micro voids can remain in the resin after filling, and macro voids can occur due to the structure shape. A transformer that is being developed has a cavity at the junction of the core and the coil for better performance, and when highly viscous epoxy flows inside the cavity channel, macro voids can form inside it. Therefore, in this study, the free-surface flow of the mold filling procedure was analyzed numerically by applying the VOF method. The results were used to understand the phenomena of void formation inside the cavity and to modify the process conditions to reduce voids.