• Journal of the Korean Society for Precision Engineering
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• v.27 no.1
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• pp.119-124
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• 2010

This paper addresses the design and fabrication of desktop die-sinking dry electrical discharge machining (EDM) system and its experimental performance analysis. The developed desktop dry EDM machine has the horizontal configuration with the size of $300{\times}200{\times}260mm$. The experimental performance analysis is conducted to investigate the effects of EDM conditions and dielectric gas temperature on the surface roughness of EDMed slots and number of EDM sparks. The experimental results demonstrate that low feed rate and large electrode displacement are good for better surface roughness and more number of EDM sparks. In addition, low temperature of dielectric gas results in better surface roughness.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.301-303
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• 2009

This paper presents a basic data of the surface discharge characteristics of solid dielectric in various gas including $SF_6$ and environmentally friendly gas as Dry-Air and $N_2$ gas. Used electrodes are needle and plane. Used solid dielectric which is installed between the electrodes is made of epoxy resin and is disc form of 100[mm] diameter and 2, 3[mm] thickness. AC In same condition, we can obtain different surface dielectric strength. Increased pressure and thickness caused increased surface dielectric strength.

• Journal of Electrical Engineering and Technology
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• v.10 no.4
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• pp.1765-1772
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• 2015

The integrity of the gas insulated switchgear (GIS) is vital to the safety of an entire power grid. However, there are some limitations on the techniques of detecting and diagnosing partial discharge (PD) induced by insulation defects in GIS. This paper proposes a joint electro-chemical detection method to resolve the problems of incomplete PD data source and also investigates a new unique fault diagnosis method to enhance the reliability of data processing. By employing ultra-high frequency method for online monitoring and the chemical method for detecting SF6 decomposition offline, the acquired data can form a more complete interpretation of PD signals. By utilizing DS evidence theory, the diagnostic results with tests on the four typical defects show the validity of the new fault diagnosis system. With higher accuracy and lower computation cost, the present research provides a promising way to make a more accurate decision in practical application.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.366-368
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• 2008

The discharge characteristics of He-Ne-Xe gas mixture with the variation of Xe content are investigated through the numerical simulation. VUV efficacy in the gas condition of low Xe content increases due to more excitation and the case of high Xe content shows the improvement of VUV efficacy with the increase of He content but decreased VUV efficacy after tthe He mixing ratio of He and Ne is 0.5 due to frequent ionization.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.4
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• pp.318-323
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• 2004

When a strong electric field is applied between a sharply curved electrode and a blunt surface, the corona may result in a gas movement in the electrode gap which is directed toward the blunt surface. That is called the corona wind. It enhances heat and mass transfer between the surface and the surrounding gas. Moreover such enhancement causes no noise or vibration, which can be applied in complex, isolated geometries, and allows simple control of surface temperatures. This paper examines the relationship between the corona wind and the relative humidity. The facility consists of high voltage power supply thin tungsten wire, plate electrode, multimeter, microammeter and flow meter. Gas velocity is a linear function of voltage, relative humidity and is proportional to the square root of the current. The maximum velocities for the positive and negative corona discharge are 1.9 m/s (2.74 CMM/m), 1.5 m/s(2.15 CMM/m), respectively.

• Proceedings of the Safety Management and Science Conference
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• 2013.11a
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• pp.547-560
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• 2013

In this study, the air pollutant removal such as sulfur oxides was studied. A combination of the plasma discharge in the reactor by the reaction surface discharge reactor Calcium hydroxides catalytic reactor and air pollutants, hazardous gas SOx, changes in gas concentration, change in frequency, the thickness of the electrode, kinds of electrodes and the addition of simulated composite catalyst composed of a variety of gases, including decomposition experiments were performed by varying the process parameters. The experimental results showed the removal efficiency of 98% in the decomposition of sulfur oxides removal experiment when Calcium hydroxides catalysts and the tungsten(W) electrodes were used. It was increased 3% more than if you do not have the catalytic. If added to methane gas was added the removal efficiency increased decomposition.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.557-557
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• 2013

Plasma hardly grows in lowpressure because of lack of collision. But low pressure plasma has useful properties because it has typically low electron density. In here, thermal electron is used to make breakdown in low pressure easily. We changed magnetic field strength and gas to control electron density or temperature. IV characteristic and electron density of the discharge are examined and the characteristic of the discharge in presence of magnetic field is also examined. Results showed that depending on the ionization cross section of the gas, electron density is changed and proper strength of magnetic field is required for high electron density.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.05a
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• pp.138-140
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• 1994

Plasma polymerized thin film was prepared using an interelectrod inductively coupled gas-flow-type reactor. Styrene was chosen as the monomer to be used. This thin films were also delineated by the electron-beam apparatus with an acceleration voltage 30kV, and the pattern in the resist was developed with RIE 80 with argon gas mixture ratio, pressure and RF power. The effect of charge of discharge power on growth rate and etching rate of the thin films were studied. The molecular structure of thin films were investigated by FIR and then was discussed in relation to its quality as a resist. In the case of Plasma polymerization, thickness of resist could be controlled by discharge duration and power. Also etch rate is increased as to growing argon gas and RF power with RIE 80.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1800-1802
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• 2003

This paper describes a study on gas dissolved distribution in oil for simulated transformer thermal faults. Experimental chamber was setup for simulation of transformer thermal faults or discharge in oil with or without insulation paper. The experimental results showed that dissolved gases in oil excluding the paper did not evolved upto $150^{\circ}C$. Hereafter the planned gas dissolved analysis will be continuously carried out for transformer fault conditions with or without insulation paper related to water absorption, arc and partial discharge.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1716-1718
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• 2003

In order to realize the PDP that is better than CRT TV, high luminance and high efficient PDP panel should be fabricated. In order to meet these conditions it is inevitable trend to use high Xe% gas working gas. In this paper, we studied the relationships between the static margin, the discharge delay and jitter of PDP and Xe% in Ne gas.