• 전기학회논문지
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• 제61권9호
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• pp.1314-1318
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• 2012

Recently, applications of plasma display to the large public display and transparent display gain much attention. With this background, we report characteristics of opposite electrodes discharge cell with long electrode gap in comparison with conventional co-planar surface discharge. The cell size of test panel is $2950{\mu}m{\times}840{\mu}m$, which corresponds to that of the display having diagonal size of 130" with XGA resolution. Electrode gap of co-planar and opposite electrode structure are $240{\mu}m$ and $500{\mu}m$ respectively. These gap dimensions provide similar driving voltage windows. Experimental results show that opposite discharge provides approximately four fold higher luminous efficacy compared with that of the surface discharge. Resulting efficacy is found to be higher than 19 lm/W in green phosphor with 10 KHz continuous pulse operation.

• 한국정보통신학회논문지
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• 제7권4호
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• pp.725-729
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• 2003

본 논문에서는 LCD 후면 광원용 한 쌍의 형광층, 방전용기 및 대향전극을 갖는 무수은 평판형광램프에 대하여 연구하였다. 구동 전압이 인가되면 균일한 방전이 램프 전체에 걸쳐서 발생한다. 방전개시전압은 가스 압력에 따라 증가한다. 이와 같은 경향은 방전 가스 압력의 증가에 의한 평균자유행정의 감소에 기인된 것으로 생각된다. 녹색 발광 평판형광램프에서 최대 2700[cd/m2]의 휘도를 얻었다.

• 전기학회논문지
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• 제67권1호
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• pp.75-81
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• 2018

In this study, the simulation of partial discharge pulse waveform have been performed for the typical joints such as EBA and PMJ in the HV underground transmission XLPE cable system in order to improve the understanding of partial discharge pulse waveform and the on-site measurement accuracy of partial discharges. FDTD simulation technique was adopted for the simulation and has been shown to be suitable for partial discharge simulation of power cables in terms of pulse propagation characteristics and waveform formation. The simulation results for the EBA showed that the second not-so-large opposite polarity peak appeared after the first negative polarity peak and the measurement sensitivity was the highest near the bottom of the EBA copper box. In the analysis results for PMJ, the magnitude of the second opposite polarity peak was large enough to compare with the first peak, and the measurement sensitivity at the end of the PMJ copper box was the highest. These simulation results show considerable similarity with the on-site measurement, and it would be very useful for the partial discharge measurement of HV XLPE cable systems.

• 물과 미래
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• 제13권1호
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• pp.49-56
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• 1980

The thesis of this analytical study includes 1) the generation of annual and monthly discharge regarding single hydrological variable at single site, 2)comparsion with the historical records and the generation, and 3) changing the monthly generatied discharge into annual. The conclusion of this will be used for the future plan for water resources development. Annual discharges at waegwan are characterized by log-normal distirbution and persistence-absent. Also, the random number generator causes the errors in the generation of annual discharge. The serial correlation coefficients of the generated annual discharge have less value than that of historical records, while the correlation coefficient and slope in January have(+) value and opposite to historical record. To change the monthly generated discharge into annual is not proper.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.609-612
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• 2002

A new reset waveform is proposed for reducing the reset period. A square pulse is applied to the address electrode while reset pulse ramps and before a discharge between the sustain electrodes occurs. The square pulse induces a discharge between the address electrode and the X electrode, and the induced wall charge is opposite to the applied ramp pulse. Thus, the next discharge between the sustain electrodes becomes weaker. The weaker discharge lowers background luminance and improves contrast ratio. Thus, the new reset waveform can reduce ramp up time in the ramp reset waveform The experimental results show that the ramp up time can be reduced by about 90% compared with the conventional ramp reset waveform.

• Journal of Korean Society for Atmospheric Environment
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• 제21권E2호
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• pp.57-65
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• 2005

An experimental study was performed on the decomposition of gaseous ammonia and two selected volatile organic compounds (VOCs: toluene and acetone) in a combined nonthermal plasma reactor with corona and glow discharges. A lab pilot scale reactor (206 liter) equipped with a high electric power pack was used to determine the decomposition efficiency in relation with the inlet concentration and applied voltage. Three different types of discharging electrode such as wired rack, wire strings for corona discharge, and thin plate for glow discharge were put in order in the reactor. While decomposition of ammonia decreased with an increase in the initial concentration, acetone showed an opposite result. In the case of toluene however no explicit tendency was found in toluene and aceton. Negative discharge resulted in high decomposition efficiency than the positive one for all gases. A better removal of gas phase element could be achieved when fume dust were present simultaneously.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 추계학술대회 논문집 학회본부
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• pp.142-144
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• 1989

Triggering characteristics of a trigatron spark gap have been studied by measuring self-emission UV light. By combining the measurement of the UV light with that of the trigger gap voltage and the lain discharge current, we distinguished clearly the differences between the trigatron operations in which the lain discharge occurs after the trigger discharge in the case of sale polarity between the trigger pin and the lain electrode at the opposite side, and the lain gap breakdown takes place before the formation of the trigger spark in the case of different polarity. We show the observation of UV radiation with the other electromagnetic measurements is a simple and reliable scheme to investigate the triggering properties of the trigatron spark gaps.

• 대한기계학회논문집B
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• 제29권1호
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• pp.151-158
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• 2005

A characteristic of discharge for a foam spray nozzle with various parameters was investigated. The discharge patterns from a fire foam spray nozzle are important to evenly spray over a maximum possible floor area. Two parameters of a foam spray nozzle were chosen, and compared with those from the standard one. Also, in order to evaluate the performance of discharged foam agents used to protect structures from heat and fire damages, the thermal characteristics of fire-protection foams were experimentally investigated. A simple repeatable test for fire-protection foams subjected to fire radiation was developed. This test involves foam generation equipment, a fire source for heat generation, and data acquisition techniques. Results show that the bubble size of foam is increased by large inside diameter of orifice or closed air hole, but phenomenon of discharge angle and expansion ratio is opposite. For the case of the open air hole, liquid film of a circular cone discharges with formation, growth, split and fine grain. In case of the closed air hole, a pillar of foam solution discharges with that. Though the temperature gradient in the foam increases with increased foam expansion ratio. it is not change with increased intensity of heat flux.

• Journal of Electrical Engineering and Technology
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• 제10권5호
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• pp.2089-2098
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• 2015

With the continuous development in insulation of electrical equipment design, the reliability of the system has been enhanced. However, in the manufacturing process and during operation under continues stresses introduce local defects, such as voids between interfaces that can responsible to occurrence of partial discharge (PD), electric field distortion and accumulation of charges. These defects may lead to localize corrosion and material degradation of insulation system, and a serious threat to the equipment. A model of three layers of PI film with air gap is presented to understand the influence of interface and voids on exploitation conditions such as strong electrical field, PD activity and charge movement. The analytical analysis, and experimental results are good agreement and show that the lose contact between interfaces accumulate more residual charges and in consequences increase the electric field intensity and accelerates internal discharges. These residual charges are trapped charges, injected by the electrodes has often same polarity, so the electric field in cavities increases significantly and thus partial discharge inception voltage (PDIV) decreases. Contrary, number of PD discharge quantity increases due to interface. Interfacial polarization effect has opposite impact on electric field and PDIV as compare to void.

• 대한전기학회논문지:시스템및제어부문D
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• 제53권3호
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• pp.166-172
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• 2004

Arc Fault Current is an electric discharge which is occurred in two opposite electrode. In this Paper, arc current control algorithm is designed for the interruption of arc fault current which is occurred in the low voltage network. This arc Is one of the main causes of electric fire. Arc fault in electrical network has the characteristics of low current, high impedance and high frequency. Conventional control algorithm does not have the arc current interrupt function. Hence, Control algorithm of arc current is designed for the interruption of arc fault current which has the modified arc characteristics.