• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.639-640
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• 2008

본 논문에서는 조작기에 의해 동작하는 초고압 SF6 가스 차단기의 냉가스 유동 해석에 대해 다룬다. 조작기 내에서 작용하는 힘들을 해석하여 나온 변위를 이용하여 차단기의 동작을 모의하였다. 차단기의 냉가스 유동 해석 시 FVFLIC 법을 이용하여 압력을 결정하였고 이것은 조작기의 힘 해석에 사용되었다. 해석 결과인 스트로크, 힘, 피스톤 전면 압력 상승은 실험 결과들과 비교하여 검증되었다.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.278-282
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• 1987

Computational and theoritical investigations of an arc plasma have been made for the design of a circuit breaker. Modeling of an arc plasma used to be very involved and difficult because of the many variables and factors, In this paper, the dynamic behavior of an arc plasma is investigated by solving the MHD equations. Comparing an $SF_6$-blast arc with a non-blast arc, it has been found that the effect of gas-blast has a great influence on density rather than temperature.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.330-332
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• 1997

In this paper, a development of the 7.2kV class $SF_6$ gas electromagnetic contactor which is used a rotary-arc principle in interrupting method is presented. A prototype contactor is made. In the interrupting small current permanent-magnet is used and in the interrupting high current the coil through which arc current itself flows is used. Successfully the prototype contactor carrys out the making, the braking and short time test.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.696-699
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• 1999

The electron transport coefficients in $SF_6+N_2$ gas is analysed in range of E/N values from 100~900(Td) by a Monte Carlo simulation and Boltzmann method, using a set of electron collision cross sections determined by the authors. The result of the Monte Carlo simulation such as electron drift velocity, ionization and electron attachment coefficients, longitudinal and transverse diffusion coefficients in nearly agreement with the respective experimental and theoretical for a range of E/N.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.3
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• pp.321-328
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• 1990

The effect of a small discharge on the A.C (60Hz) breakdown characteristics in SF6 gas has been studied. Various experiments were investigated while varying distance of the rod-plane electrode, the gas pressure, and the magnitude of the small discharge current. Also, the position of the discharge path was observed for the purpose of evident investigation. As the results of this study, authors clarified the shifting mechanism of the position of discharge path with the ratio Rn (E/N distribution at a certain higher tempera-ture due to the small discharge current to E/N distribution at room temperature, E:electric field strength, N:particle number density). Also, the reason for the reduction of the A.C. breakdown voltage was investigated in the presence of a small discharge current.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.165-168
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• 1999

The electron transport coefficients in mixture gas includes SF/sub 6/ is analysed in range of E/N values from 60∼800(Td) by the Boltzmann method that using a set of electron collision crass sections determined by the researchers. Swarm parameters in the Boltzmann method simulation such as electron drift velocity, ionization and electron attachment coefficients is in nearly agreement with the respective experimental and theoretical for a range of E/N.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.592-595
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• 2000

The electron transport coefficients in $SF_6$+$N_2$ gas is analyzed in range of E/P values from 70~240(V/cm $Torr^{-1}$) at 2$0^{\circ}C$ by Boltzmann method that using set of electron collision cross sections determined by authors. The result of this Boltzmann simulation such as ionisation coefficient, attachment coefficient, effective ionisation coefficient and breakdown voltage are in nearly agreement with the respective experimental and theoretical for a range of E/P.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.938-941
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• 2000

SrBi$_2$Ta$_2$$O_{9}$(SBT) thin films were etched in Ar/SF$_{6}$ and Ar/CHF$_3$gas plasma using magnetically enhanced inductively coupled plasma(MEICP) system. The etch rates of SBT thin film were 1500$\AA$/min in SF$_{6}$/Ar and 1650 $\AA$/min in Ar/CHF$_3$at a rf power of 600W a dc-bias voltage of -l50V. a chamber pressure of 10 mTorr. In order to examine the chemical reactions on the etched SBT thin film surface , x-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS) were examined. In etching SBT thin film with F-base gas plasma, M(Sr. Bi. Ta)-O bonds are broken by Ar ion bombardment and form SrFand TaF$_2$ by chemical reaction with F. SrF and TaF$_2$are removed more easily by Ar ion bombardmentrdment

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.297-299
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• 2005

In this paper the experiments of insulation characteristics by temperature change of $SF_6$ gas in model GIS(Gas Insulated Switchgear) were described. From this results, the breakdown voltage was increased with a drop of temperature and an increase of the inner pressure in model GIS. It is considered that these result are fundamental data for electric insulation design of superconductor and cryogenic application machinery which will be studied and developed in the future.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1992.05a
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• pp.140-143
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• 1992

This paper deals with the dielectric behaviors of $SF_{6}$ gas and prebreakdown growth caused by lightning impulse voltages in inhomogeneous field perturbed with a fixed needle-shaped protrusion on the electrode. The measuring interpretation of the external current induced by moving charges is described. The temporal growth of prebreakdown is obserbed by using a shunt and photomultiplier. The prebreakdown processes are initiated by the first streamer corona at a needle protrustion, the flashover of the main gap in the positive polarity is very sensitive to the local field and propagates into the gap with the leader mechanism. It is found that the dependence of the prebreakdown phenomena on the polarity of applied voltages is caused by the effect of space charges. In addition, the proposed measuring techniques are very useful to perform the measurements of avalanche currents, corona discharges in inhomogeneous fields ad partial discharges in voids.