• Progress in Superconductivity and Cryogenics
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• v.6 no.1
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• pp.22-27
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• 2004

It is important to mechanical properties of dielectric paper and cable to optimum electrical insulation design of HTS cable, because the cable has experience of mechanical stress, such as tensile stress, bending stress. Also, it is operated at cryogenic temperature. From the results, it was observed that the tensile strength of PPLP in liquid nitrogen was high more than that of air, but tensile strain decrease sharply. According as tensile strength increases, the breakdown stress of PPLP in liquid nitrogen is decreased. Because PPLP was deteriorated by microcrack and tensile strain. According as bending radius multiple is decrease, the ac and impulse breakdown stress of mini-model cable is sharply decreased.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.2
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• pp.19-23
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• 2014

In this paper the experiments of breakdown characteristics of rod-electrodes by pressure and gap change of imitation-air were described. The results are fundamental data for electric insulation design of distribution power facilities which will be studied and developed in the future. And we could make an environment friendly gas insulation material with mataining dielectric strength by imitation air which generates a lower lever of the global warming effect.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.8
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• pp.16-20
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• 2013

In this paper the experiments of breakdown characteristics by pressure and gap change of imitation air were described. The results are fundamental data for electric insulation design of distribution power facilities which will be studied and developed in the future. And we could make an environment friendly gas insulation material with mataining dielectric strength by Imitation Air which generates a lower lever of the global warming effect.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.12
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• pp.77-82
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• 1996

The breakdown characteristics of metal-oxide-semiconductor(MOS) capacitors fabricated by Al, polysilicon, and tungsten polycide gate electrodes onto gate oxide was evaluated by time zero dielectric breakdwon (TZDB). The average breakdown field of the gate oxide with tungsten polycide electride was lower than that of the polysilicon electrode. The B model (1~8MV/cm) failure of the gate oxide with tungsten polycide electrode was increased with increasing annealing temperature in the dry $O_{2}$ ambient. This is attributed ot fluorine and tungsten diffusion from thungsten silicide film into the gate oxide, and stress increase of tungsten polcide after annealing treatment.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.7
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• pp.675-681
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• 2005

$SF_6$ is widely used as gas insulation medium because of having excellent dielectric and arc-quenching properties. However the use of it is getting to be suppressed from the viewpoint of mitigating global warming. For the development of environmentally-benign electric power equipment and system, novel gases or mixture gases are strongly required as the substitute of $SF_6$ gas. In this study the authors constructed an experimental system to investigate insulation properties of the mixed gases composed of negative $gas(SF_6)$ and electron deceleration gases$(N_2\;and\;CO_2)$. Breakdown and prebreakdown characteristics of $SF_6/N_2/CO_2$ mixture gases were investigated using the above mentioned system for different rates and gas pressures.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.289-290
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• 2008

The purpose of this paper is to analyze AC Breakdown of solid/air composite insulation depending on the thickness and the pressure of dry air for eco-friendly insulation. SF6 gas has been widely used in electric equipment as gas insulation because of high dielectric strength and arc extinguishing performance. However, because SF6 gas is one of the green house effect gases, alternative insulation such as SF6 mixture, extremely low temperature gas, vacuum, liquid and solid insulating are being investigated.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.4
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• pp.164-168
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• 2002

The main hazard leading to breakdown in GIS(Gas Insulated Switchgear) comes from free conducting particles, which can cross between tee electrodes and cause dielectric failure under the influence of the electric field. Bouncing height of the particle can be an important factor to evaluate the possibility of breakdown occurrence. In this paper, how to estimate, outside a GIS, the bouncing height of the particle was newly suggested when GIS is in service. Both experimental results using 362 kV test chamber and computer simulation results on estimating the height were presented and compared with each other.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.136-139
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• 2000

Epoxy materials are used as insulation material for electric power cables. In the case of a flow of excess current due to the temperature difference which occurs between the heat of the conductor and the atmosphere, heat degrades connection point of the cables. Also, the mechanical stress, which occurs due to the thermal expansion coefficient of cable connection electrode system and epoxy insulation materials along with the gap between thermal conduction based on the extra high voltage of transmitted voltage, increases possibility of cracks to occur. The relationship between mechanical stress and electrical breakdown mechanism is verified for the epoxy materials such as high toughness epoxy materials, which comes to be used contemporarily, and for the breakdown mechanism of epoxy materials on the multi-stresses (mechanical and electrical) due to the variation of the temperature.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2271-2273
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• 2005

The cyclic aging for 14days is performed in order to remove the large amount of the volatiles contained in freshly manufactured cable. And the accelerated water treeing test(AWTT) is performed to accelerate the occurance of the water tree in the dielectric of XLPE. In this paper, we examined the AC breakdown voltage characteristics of the 22.9kV power cable before and after the cyclic aging for 14days and the AWTT. As the result, the AC breakdown voltage of the TR CNCV-W power cable is higher than that of CNCV-W and FR CNCO-W power cable.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.254-255
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• 2007

This paper describes underwater discharge phenomena which are less studied than gas, solid and dielectric liquid. Since discharge phenomena were affected by various factors, we investigated the effect of water resistivity in point-plane gap by impulse voltage. In discharge photograph, it is hard to discover the streamer development in positive polarity at high reisistivity. On the other hand, the streamer originated at the tip of rod and developed toward the plane with increasing voltage. It is found that the breakdown voltage of both polarities in lower resistivity are lower than that of high resistivity. High current flowing in lower resistivity before the breakdown induce more streamer and enhance the probability of breakdown.