• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.523-524
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• 2006

본 논문에서는 질소와 이산화탄소를 완충기체로 사용하는 경우의 혼합가스에 대해 가스절연설비 내부의 이물질에 의한 절연파괴특성을 모의하기 위한 침-평판 전극구조에서의 침전극 재질을 연철, 고탄소강, 스테인레스강 등으로 구성한 경우 혼합가스의 절연파괴 특성에서 나타나는 전극 재질에 의한 영향을 실험적으로 검토해 보았다. 실험 결과 연철제 전극과 고탄소강제 전극의경우에는 혼합가스의 절연파괴특성에서 유사한 N-특성이 나타남을 확인할 수 있었으나 스테인레스 강제 전극의 경우에는 다소 상이한 양상이 나타났다. $SF_6$계 혼합가스의 경우에는 순 $SF_6$의 경우와 동일하게 코로나 안정화작용에 의한 N-특성이 발현됨이 일반적인 특성으로 알려져 있으나 본 실험 결과에 의하면 침전극 재질에 따라 다소 상이한 양상이 나타날 수 있음을 관측하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.234-235
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• 2005

본 논문에서는 전력용 케이블에서 초고압으로 사용되고 있는 가교폴리에틸렌 내부(XLPE)에 침투된 침전극의 곡률반경변화에 따른 XLPE의 전계분포를 경계요소법에 의한 3차원 시뮬레이션 프로그램을 통하여 해석하여, 곡률반경이 작을수록 전계가 집중되는 현상을 확인하였다.

• Proceedings of the KIEE Conference
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• 1985.07a
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• pp.210-211
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• 1985

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.2
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• pp.128-133
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• 2008

This paper describes underwater discharge phenomena and breakdown characteristics in case that the standard lightning impulse voltage is injected to the needle and spherical electrodes installed in the hemisphere water tank. The objective of this work is to understand the basic features related to transient ground impedance against lightning surges. The discharge luminous images were observed and the dependence of breakdown voltage on the polarity of applied voltage and water resistivity were investigated. As a consequence, streamer corona is initiated at the tip of needle and spherical electrodes and is propagated toward grounded tank with stepwise extension. The breakdown voltage characteristics measured as a function of water resistivity showed V-shaped curves. Breakdown voltage and time curve of needle electrode is higher than that of spherical electrode.

• Journal of Sensor Science and Technology
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• v.7 no.2
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• pp.140-146
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• 1998

Methods and systems to remove static electricity are requested necessarily because the static electricity causes a flammable gas explosion, a fire, reduction of production rate in manufacturing VLSI semiconductor device and so on. In this paper, abrasion and dust contaminant of needle electrode are studied experimentally. And, frequencies and pulse durations of a high frequency pulse source were controlled effectively to minimize the abrasion of needle electrode and control generated numbers of ions. As a result, it is verified experimentally that the ion generation of charge neutralizer increases by using a high frequency pulse source.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.8 no.3
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• pp.54-63
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• 1994

In this paper, we fixed to the needle electrode on the plate spacer fabricated the plate electrode of the gap interval 40[mm]and divided into the interval lO[mm]in the gap. When set up the particle and barrier on the material as well as spacer in the each intervaL We investigated that FOV and discharge path to AC, OC positive polarity. The results are as follow. 1) When the barrier is settled on the high potential side and the particle is hidden on the back of barrier, FaV has been increased. 2) When the particle is located on the tip of needle electrode, FaV has been decreased considembly. 3) When the particle is between electrodes. FaV has been decreased because discharge path through the particle.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.79-80
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• 2006

본 논문에서는 초고압전력용 케이블에서 절연재료로 사용되고 있는 가교폴리에틸렌 내부(XLPE)에 침투된 침전극의 기울기변화에 따른 XLPE의 전계분포를 경계요소법에 의한 3차원 시뮬레이션 프로그램을 통하여 해석하여, 약 $20^{\circ}$의 기울기에서 전계가 집중되는 현상을 확인하였다.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1202-1204
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• 1995

In this paper, We investigated a charge elimination by using a needle electrode in order to prevent the electrification phenomena of insulating oil flowing by force at the internal transformer. In our experiment, We used Acryle and Teflon as the material of charge reducer and measured each of their streaming current and needle electrode current. As a result of experiment, We can explain that the current of needle electrode increase in proportion to insulation of charge reducer.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.11a
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• pp.239-241
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• 2007

In this paper we describe streamer propagations characterizing underwater pre-breakdown and breakdown behaviour under impulse voltages. Streamer corona branches in lower resistivities are much thicker and brighter than those in higher resistivities. The negative streamer channels not only have more branches but also widely spread out than the positive streamer channels. The succession of streamer coronas during re-breakdown produces a stepwise propagation. The pre-breakdown currents consist of the conduction current and streamer corona current pulses.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.3
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• pp.604-608
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• 2010

An electric fan for cooling high density electronic devices is limited and operated in very low efficiency. The corona discharge is utilized as the driving mechanism for an ionic gas pump, which allows for air flow control and generation with low noise and no moving parts. These ideal characteristics of ionic pump give rise to variety applications. However, all of these applications would benefit from maximizing the flow velocities and yields of the ionic pump. In this study, a needle-mesh type ionic pump has been investigated by focusing on the radius of curvature of corona needle points elevating the ionic wind velocity and efficiency. It is found that the radius of curvature of the corona discharge needle point influences significantly to produce the ionic wind and efficiency. As a result, an elevated ionic wind velocity and increased ionic wind generation yield can be obtained by optimized the radius of curvature of the corona needle electrode.