• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.85-85
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• 2010

In this paper, each specimen blended at weight proportions of 80% HDPE to 20% EVA, 70% HDPE to 30% EVA, 60% HDPE to 40% EVA, and 50% HDPE to 50% EVA was manufactued respectively. FE-SEM, DSC and XRD analysis were carried out as the means of structural and chemical analysis. From the results of DSC and XRD analysis, the lower contents in blended specimens were, the higher melting temperature and crystallinity of main crystal were. It seems that the phenomena was attributes to themoplastic interpenetrating network effect(TPIPN) in which EVA having low melting point penetrated into HDPE. Also, from the decreasing tendeancy of melting point as a function of blend ration, it was confirmd that above resins have compatibility. The thermal and mechanical performance of proposed insulator were compared with conventional XLPE, main insulating material of CV cable. Also, validity was proved by superior and inferior factor respectively.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1498-1501
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• 1996

To evaluate insulating properties of polyimide thin film on high temperature over $100\;^{\circ}C$, polyimide film were prepared by electrophoretic deposition onto metal surface from nonaqueous emulsion. The emulsion is made by adding a solution of the resin to a precipitant, which is an organic liquid compeltely miscible with the solvent of the organic resin solution, but which does not dissolve the resin. The polyimide film obtained by annealing shows good insulation properties of 5.8 MV/cm at elevated temperature and breakdown strength of the film reveals thickness dependence.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전기설비전문위원
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• pp.77-79
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• 2004

It is caused that insulation paper, which had got a lot of thermal stress by over-load after installation, should have been deteriorated in electrical and mechanical characteristics. Beside, insulation material is decreased the insulating property and accelerated aging of them in case of dielectric loss when transformers are manufactured with some moisture or transformers would have been them because of moisture-permeation. Therefore, in this study we experienced the influence of moisture content in case of the thermal aged insulation paper. we have measured tan 6 and breakdown voltage in the ratio of paper' moisture content before the aging and then taken the same tests again after insulation paper thermally accelerating-aged. There is a purpose to gain data for a life-design and to establish aging mechanism in order to continuously study life expectancy of the insulation paper

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.1143-1144
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• 2015

반절연 4H-SiC 기판을 이용한 LDIMOSFET에 대해 전류 통전 영역의 길이에 따른 항복전압 및 순방향 특성을 분석하였다. 또한, 온도 변화에 따른 역방향 상태 및 벌크 트랩 유무에 따른 누설전류 특성을 분석하였다. 전류 통전 영역의 두께를 $0.2{\mu}m$로 고정시키고 농도를 $1{\times}10^{15}/cm^3{\sim}1{\times}10^{17}/cm^3$ 까지 변화하였을 때 $2{\times}10^{16}/cm^3$인 경우에 1710V로 가장 높은 항복전압을 나타내었으며, 농도가 $2{\times}10^{16}/cm^3$ 이상인 경우 항복전압은 감소하는 특성을 나타내었다. 제안한 소자의 순방향 특성에 대해서도 simulation을 통해 특성을 분석하였으며, 항복전압이 1710V인 경우 온 저항은 $0.351{\Omega}-cm^2$를 나타내었다. 또한 벌크 트랩이 있는 경우에 대해 온도 변화 및 전류 통전 영역의 길이 변화에 따른 역방향 바이어스 상태에서의 누설전류 특성 변화에 대해서도 분석하였다.

• 한국안전학회지
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• 제21권6호
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• pp.26-32
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• 2006

The paper considers the electrical shock risk of the human body due to underwater leakage current in electric field. The characteristics of electric shock in fresh water due to the leakage of submerged electric facility in the bathtub in public baths were conducted. The exposed live electrode is modeled as a point source of electric current source. It is assumed that divergent monopole field exists in the vicinity of the current source, regardless of the presence of return electrode and insulating boundary. The electric potentials in the steel bathtub, Diesen and Mole and Flux3D program one are measured according to the distance from leakage source. The results show that the increased shock risk and safe distance are estimated by the bathtub of limited width and the voltage calculated on the basis of a divergent monopole field concept is compared with the measured value.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.100-103
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• 2003

The primary insulation system used in an oil-filled transformer is kraft paper, wood, porcelain and oil. Modern transformers use paper that is chemically treated to improve its tensile strength properties and resistance to aging caused by immersion in oil. But these insulation papers are mainly aged to thermal stress. Over the course of the insulation paper and oil's life it is exposed to high temperatures, oxygen and water. Its interaction with the steel of the tank and core plus the copper and aluminium of the windings will eventually cause the chemical properties of the oil to decay. High temperature have an effect on mechanical strength of cellulous paper using the layer insulation. We made two aging cell in which thermal aging tests of insulation papers and mineral oil are conducted. It is measured dielectric strength, number of acid, moisture, etc. of insulation paper and oil aged in the aging cells.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.605-608
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• 2001

With the intention of investigating the breakdown properties of oil-immersed transformer oils in temperature range of $20\sim100[^{\circ}C]$, we are made researches AC breakdown in the gap of $500\sim2500[{\mu}m]$. The classification for the physical properties of oil for oil-immersed transformer by FTIR and H-NMR experiments was confirmed to type of mineral oils. As the dependance of breakdown properties due to electrode gap length variation, breakdown voltage was found increasing according to the increase of gap, while dielectric strength was decreasing. As a result the characteristics for AC breakdown, It goes to prove that the breakdown voltage was increased to $90[^{\circ}C]$ but decreased over $90[^{\circ}C]$ in the temperature range. Also, breakdown voltage was found increasing in the increase of gap and the rising of temperature according to Weibull distribution.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.251-254
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• 2001

In this paper, we analyzed the properties change of electric wire when the thermal stress was applied to NFR-8 and FR-PVC 600[V] wire. Messurement is made of the attenuation of a light beam by smoke accumulating with in a closed chamber due to nonflaming pyrolytic decomposition and flaming combustion. Results are expressed in terms of specific optical density which is derived from a geometrical factor and the measured optical density a measurement characteristic of the concentration of smoke. Referenced documents were ASTM E662 standard test method for specific Ds genalated by solid materials. The furnace control system shall maintain the required irradiance level under steady-state condition with the chamber door closed of $2.5{\pm}0.04[w/cm^{2}]$ for 20 min. According to the results of the smoke density analysis of NFR-8 and FR-PVC the highest decomposition flaming smoke density range of NFR-8 and FR-PVC were 25.2 to 37.5 and 51.1 respectively. Nonflaming smoke density range of NFR-8 and FR-PVC were 100.4 to 112.2 and 126.5 to 398.8. The amount of carbon monoxide generated was found to be much higher in FR-PVC decomposition than in NFR-8 due to incomplete combustion of FR-PVC which has high content of carbon in compound.

• 한국진공학회지
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• 제19권5호
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• pp.385-390
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• 2010

원자층 증착법(Atomic Layer Deposition, ALD)을 이용하여 ZnO 나노막대에 ZnO:Al과 $Al_2O_3$를 코팅하여 coaxial 형태의 나노선 구조를 제작하여 광학적 특성을 분석하였다. 반도체인 ZnO:Al을 코팅하는 경우 Al이 ZnO층에 확산되어 ZnO에 도핑이 되는 효과를, $Al_2O_3$를 코팅하는 경우 반도체-절연체 계면 상태가 존재함을 광전이 특성을 이용하여 확인하였다.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2006년도 춘계학술발표논문집
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• pp.203-206
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• 2006

The sensor consists of a heater, an insulating layer, a pair of contact electrodes, and CNT-sensing film on a micromachined diaphragm. The heater plays a role in the temperature change to modify sensor operation. Gas sensor responses of CNT-film to $NO_2$ at room temperature are reported. The sensor exhibits a reversible response with a time constant of a few minutes at thermal treatment temperature of $130^{\circ}C$.