• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1633-1635
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• 1994

This paper presents the development technology of standard resistor divider for full lightning impulse voltage. The ability of high voltage bulk power equipment to withstand lighting stroke is usually evaluated by means of full lightning impulse voltage. Lightning impulse voltage test has been essential to evaluate the insulation performance of electrical power apparatus. Recently International standard (IEC 60) on high voltage measurement techniques is being revised and requests a formal traceability of high voltage measurements. Therefore, general interest for this area has grown considerably during last years, and several international intercomparisions have been completed already worldwide, i.e. Europe, Japan, America etc.. In this viewpoint, we have also investigated the standard resistor divider with shield, which satisfies the IEC recommendation.

• 대한전기학회논문지
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• 제45권2호
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• pp.283-288
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• 1996

This paper presents the development technology of standard shielded resistor divider for full lightning impulse voltage. The ability of large-capacity power apparatus to withstand lighting stroke is usually evaluated by means of full lightning impulse voltage. Lightning impulse voltage test has been essential to evaluate the insulation performance of electrical power apparatus. Recently international standard (IEC 60) on high voltage measurement techniques is being revised and requests a formal traceability of high voltage measurements. Therefore, general interest for this area has grown considerably during last years, and several international intercomparisons have already completed worldwide, i.e. Europe, Japan, America etc., In this viewpoint, we have also investigated the step response of the standard shielded resistor divider, which satisfies the IEC recommendation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
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• pp.1962-1964
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• 2006

In this paper, the dynamic models of SOFC are suggested. It consists of electrochemical model, thermal model, voltage equation and several loss equations. Control problems on tracking steady voltage by air flow is discussed and an adaptive controller is designed to withstand to the variation of stack current. Simulation is done to prove the solution of control algorithms.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 D
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• pp.2516-2518
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• 2005

In this paper, the dynamic models of SOFC are suggested. It consists of electrochemical model, thermal model, voltage equation and several loss equations. Control problem on tracking steady voltage by air flow is discussed and an adaptive controller is designed to withstand to the variation of stack current. Simulation is done to prove the solution of control algorithms.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 춘계학술대회 논문집
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• pp.93-99
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• 2000

Using the EMTP(Electro Magnetic Transient Program) for the analysis of lightning direct voltage on the railway system, the shielding effects of overhead grounding wire on the railway were studied quantitatively. Installation of overhead ground wire and gap-type arrester such as s-horn Provides a 6.6㎸ HV distribution line with good protection effects. Even severe lightning induced voltage were create, 6.6㎸ HV lines can be withstand.

• 한국전기전자재료학회논문지
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• 제33권1호
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• pp.60-64
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• 2020

In this study, to develop angle ring pressboards for high voltage transformers, the radius and thickness are modified under the conditions of temperature and humidity. In particular, a pressboard with a thickness of 6 mm and a radius at the angled part were investigated based on the simulation of the principal stress from the angled optimization profile shape. As a result, by the appropriate application of a higher temperature, the solid insulation can be improved to reduce the moisture content for an optimized profile angle of a high voltage transformer. This also results in the improvement of the safety factor by 25%. It is determined that the electrical insulation properties of pressboards in high voltage transformers can be enhanced by improving their properties.

• Elastomers and Composites
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• 제36권4호
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• pp.262-267
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• 2001

내전압 특성과 항균성을 갖는 절연 고무장갑을 제조하기 위해 천연고무 라텍스 (NRL)와 수분산성 폴리우레탄 (PU) 그리고 4급 아민 키토산 (4N-chitosan)을 배합하여 침지법으로 제조하였다. 절연 고무장갑의 기계적인 특성은 폴리우레탄 함량이 증가할수록 인장강도는 증가하였으나 신장율은 저하되었으며, 노화후 인장강도 및 신장율의 잔존율은 폴리우레탄 함량 증가에 따라 증가하였다. 또한, 리칭시간이 증가할수록 내전압 특성이 증가하였으며, 3시간의 리칭시간에서 10000V의 내전압 성능을 나타내었다. 고무장갑에 4N-chitosan을 첨가한 결과 균이 거의 생존하지 않았다.

• 조명전기설비학회논문지
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• 제24권10호
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• pp.78-84
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• 2010

This paper describes the safety assessment of power cable splices connecting different sized 6/10[kV] class power cables. To assess the safety, AC withstand voltage tests, partial discharge tests and impulse tests were carried out to the cable splice specimens and thermal rise due to overload and cross section of joint were examined as well. As a result, a breakdown due to the $4.5[U_0](27[kV_{ac}])$ application could not found for 5 minutes. Under $1.73[U_0](10.4[kV_{ac}])$ application, partial discharges of 4~8[pC] were detected. In impulse tests, all the specimens withstood to the standard waveforms of $75[kV_{peak}](1.2{\times}50[{\mu}s])$ without any breakdowns. In addition, the temperature on the splice rose by $3[^{\circ}C]$ when the 200[A] flew through the splice for 20minutes, however the thermal rise of $3[^{\circ}C]$ was considered due to the atmospheric temperature. After all the electrical tests, the cross section of the splice was visually examined. The conditions of the conductors of both $185[mm^2]$ and $240[mm^2]$ were good.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 방전 플라즈마 유기절연재료 초전도 자성체연구회
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• pp.94-99
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• 2004

This paper presents experimental data from model windings with different arrangement of coil in order to provide information to design a 22.9 kV class HTS transformer. Before experiment, the composite insulation of two different type of HTS transformers are investigated. The first basic of investigation is a breakdown characteristic of liquid nitrogen and flashover characteristic on the GFRP surface under ac and impulse, The second investigation is insulation design, manufacture and test of model windings. These include a AC withstand voltage test of 50 kV rms and a lighting impulse test of 150 kV at peak.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.2114-2115
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• 2008

We consider the relation between on-line monitoring and diagnostics on the one hand and high-voltage (HV) withstand and partial discharge (PD) on-site testing on the other. HV testing supplies the basic data (fingerprints) for diagnostics. In case of warnings by on-line diagnostic systems, off-line withstand and PD testing delivers the best possible information about defects and enables the classification of the risk. Frequency tuned resonant (ACRF) test systems are best adapted to on-site conditions. They can be simply combined with PD measuring equipment. The available ACRF test systems and their application to electric power equipment -from cable systems to power transformers is described.