• 조명전기설비학회논문지
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• 제24권7호
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• pp.41-46
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• 2010

With the improvement of industrial society, high quality electrical energy, simplification of operation and maintenance, and ensuring reliability are being required. Also we request an urgent change from $SF_6$ gas to an environment-friendly gas insulation material. In this paper, the experiments of breakdown characteristics by pressure and gap change of $N_2/O_2$ mixture gas through a GIS (Gas Insulated Switchgear) model were described. This paper reviews basic data of the surface discharge characteristics for Teflon resin in not only pure $N_2$, $N_2:O_2$ mixture gas as being focused on environmentally-friendly insulating gas, but also $SF_6$. Also, insulation characteristics by breakdown voltage and surface discharge voltage of $N_2:O_2$ mixture gas in the experimental chamber were studied.

• 조명전기설비학회논문지
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• 제21권2호
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• pp.20-27
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• 2007

정보화 시대로 변화함에 따라 고품질 전력의 중요성이 강조되고 있으며 이를 보장하기 위한 전력기기 운전의 신뢰성 향상이 선결과제로 대두되었다. 특히 대용량 전력기기 중 개폐기와 차단기의 성능을 일정 수준 이상으로 유지하기 위한 예방진단기술이 발달되어 왔다. 개폐기와 차단기에서 많이 사용되는 $SF_6$ 가스의 절연성능을 검출하여 유지보수 여부를 결정하는 것이 매우 중요하다. 본 연구에서는 이러한 $SF_6$ 가스의 절연성능을 검출하기 위해 사용되는 여러 가지 방법 중에 전기방전에 의해 나타나는 여러 현상을 검출하는 센서들의 기초특성을 확인하고 파악된 특성을 통해 복수의 검출센서를 사용할 것을 제안하였다. 즉 코로나 방전이나 아크방전 시에도 사용할 수 있는 UHF 센서와 방전전류 검출기를 병용하는 것이 $SF_6$ 가스의 절연성능 확인에 유리할 것으로 판단되었다. 이외에도 가스센서를 이용한 $SF_6$ 가스의 절연상태 검출을 시도해 그 가능성을 시험해 보았다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1382-1384
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• 1995

In order to study the structure of RF glow discharge driven at 13.56MHz in argon, the discharge voltage, current and phase shift between them will be measured over a wide range of discharge parameters(gas pressure between 1mTorr and 50mTorr with discharge power between 20mW and 200W). In this paper, the dc glow discharge characteristics and plasma parameters of both FTS and CPMS systems are studied experimentally. It is found that for CPMS system discharge is stablized under wider ranges of magnetic field and pressure than for FTS system. The plasma density and electron temperature of the plasma for these two systems are in the range of $10^{10}{\sim}7{\times}10^{11}[cm^{-3}]$ and $3.5{\sim}6.5$[eV], respectively.

• KIEE International Transactions on Electrophysics and Applications
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• 제2C권6호
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• pp.297-303
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• 2002

We have developed an on-line ultrasonic detector to monitor partial discharge in an operating transformer. The ultrasonic sensor has 150[KHz] resonance frequency and contains a pre-amplifier with 60[㏈] gain. The on-line ultrasonic detector has 50~300[KHz] frequency band-pass filter to remove electrical and mechanical noises from the transformer. This detector has an ultrasonic signal discrimination algorithm which discriminates ultrasonic signals due to partial discharge in a transformer. A moving average method of ultrasonic signal number was employed to effectively monitor the increasing trend of the partial discharge. This paper describes an experience of partial discharge detection in a 154[㎸] operating transformer using an ultrasonic detector. With regards to gas analysis in oil, C2H2 gas was produced with a warning level in this transformer We detected ultrasonic signals on the transformer steel wall, and estimated the position of partial discharge. With further inspection, we found carbonized marks due to partial discharge on the supporting bolt which fastens the windings.

• 대한전기학회논문지
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• 제39권3호
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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.

• 대한화학회지
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• 제34권5호
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• pp.396-403
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• 1990

일반적인 화학증기증착(CVD : Chemical Vapor Deposition)실험에서 반응기작을 연구할 수 있는 LPCVD (Low Pressure CVD) 장치의 설계 및 제작에 관한 것과, 특히 이 장치를 이용하여 메탄, 수소의 혼합기체와 헬륨을 완충(buffer) 가스로 사용하여 p-type (111) Si wafer 위에 다이아몬드 박막(diamond film)을 얻고자 시도한 것에 대하여 기술하였다. 실험은 두 가지 방법으로 나누어서 행하였다. (1) Si wafer를 반응기 안에 있는 heater(약 480$^{\circ}C$)위에 놓고 두 개의 다른 inlet 가스관을 사용하여 실험하였다. Posphoric acid로 coating된 하나의 관은 microwave discharge시킨 수소 기체를 흘려주는데 사용하였고, 다른 관은 discharge시키지 않은 메탄 기체를 흘려주는데 사용하였다. 그 결과로 무정형 탄소 뭉치 화합물(amorphous carbon cluster)을 얻었다. (2) 수소와 메탄을 동시에 discharge시켜 plasma 상태인 discharge tube안에 Si wafer을 넣고 증착시켜, 그 결과로 다이아몬드 구조를 갖은 반응생성물을 얻었다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.1237-1240
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• 2005

The effects of various sustain waveforms on the discharge characteristics, such as discharge current waveform, IR waveform, luminance, luminous efficiency, power consumption, and static margin are investigated under high Xe (20%) gas mixture at 200 kHz. The four types of sustain waveforms, such as non-overlapped sustain waveform without auxiliary pulse, non-overlapped sustain waveform with auxiliary pulse, overlapped sustain waveform without auxiliary pulse, overlapped sustain waveform with auxiliary pulse, are examined intensively. As a result, the overlapped sustain waveform with auxiliary pulse shows the best discharge characteristics under high Xe (20%) gas mixture at 200 kHz.

• E2M - 전기 전자와 첨단 소재
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• 제8권6호
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• pp.721-726
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• 1995

In this paper, reduction characteristics of NOx gas produced from diesel engine combustion is studied by using pulse corona discharge. Nox concentration of 1900ppm (NO 1870, NO$\sub$2/ 30 ppm, N$\sub$2/ balance gas) was controlled in a fixed quantity of 280ppm, using a flow meter. Reactors are composed of cylinder type. NOx reduction rate is investigated with discharge electrode diameter[0.5,1,3,4.phi.], reactor length [130,300mm], reactor materials[Copper, Poly Vinyl Chloride] and Input voltage[DC, AC, DC Pulse square voltage]. In the result, NOx reduction rate is the best of all in copper reactor, small electrode diameter[0.5.phi.], DC pulse voltage and long reactor[300mm]. Then Teduction rate of NOx is about 93%.

• 한국전기전자재료학회논문지
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• 제13권3호
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• pp.265-272
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• 2000

In this paper the corona discharge in SF$_{6}$ gas used as insulating material in lots o high voltage equipment, is simulated by finite element method with Flux-Corrected Transport(FCT) method. By application of proposed method the negative corona discharge characteristics in needle to plane electrode is analyzed with time step. For the accuracy of analysis the secondary electron emission by photon and ion are also considered as well as the accuracy of analysis the secondary electron emission by photon and ion are also considered as well as townsend first ionization and electron attachment. The calculated results show that the electric field intensity between anode and ion group is decreased as times go-by according to field distortion by those space charge. Accordingly the electron density is decreased strongly by the attatchment effect of SF6 gas so that the corona discharge becomes extinguished abruptly.y.

• 공업화학
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• 제33권2호
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• pp.229-233
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• 2022

In this study, a gas-liquid hybrid atmospheric pressure plasma reactor of the dielectric barrier discharge method was fabricated and characterized. The solubility of copper oxide in the organic acid solution was increased when argon having a larger atomic weight than helium was used during plasma discharge. There was no significant effect of mixing organic acid solutions under plasma discharge treatment on the variation of copper oxide's solubility. As the applied voltage for plasma discharge and the concentration of the organic acid solution increased, the dissolution and removal power of the copper oxide layer increased. Solubility of copper oxide was more affected by the concentration in organic acid solution rather than the variation of plasma applied voltage. The usefulness of hybrid plasma reactor for the surface cleaning process was confirmed.