• Title/Summary/Keyword: Electrical Discharge

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A study on the arc discharge characteristics of liquid insulating materials for electrical discharge machine (방전가공기용 액체 절연재료의 아크 방전 특성 연구)

  • 김상현;김해종;마대영;신태민
    • Electrical & Electronic Materials
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    • v.8 no.5
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    • pp.564-571
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    • 1995
  • This paper deals with the arc discharge characteristics of kerosene oil as a basic study on electrical discharge machine. Using needle electrode the discharge voltage, discharge current, discharge energy and the shape of discharge crater are measured. In consequence, it becomes clear that the discharge crater(depth, height, diameter) is depending on the discharge energy. Rapid increase in depth, height and diameter of discharge crater was observed during initial discharge, where discharge energy is large. However, rather slow decrease of those values was found when discharge energy is low or N is more than 3. As the ratio of $I_p$$T_on$ increase, the shape of discharge crater gets near circle. The protuberances of the discharge crater were not formed by the melted needle electrode but by the that of work piece.

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The effects of discharge gases in the voltage transfer curve of ac-PDP (ac-PDP의 전압전달특성에 미치는 방전가스의 영향)

  • Son, J.B.;Lee, S.H.;Kim, D.H.;Kim, Y.D.;Cho, J.S.;Park, J.H.
    • Proceedings of the KIEE Conference
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    • 1999.07e
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    • pp.2233-2235
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    • 1999
  • The ac plasma display panel(PDP) is a flat light-emitting gas discharge device. Discharge gases directly take effects to the discharge phenomena of ac PDP. Therefore it is necessary to understand the characteristics of the discharge gases. In this paper, we have studied the effects of discharge gases by voltage transfer curves which show the discharge characteristics of ac PDP and the change of the effective wall capacitance during a discharge which depends on lateral spreading of charge distribution and the strength of discharge. As gas pressure increases, memory margins increases. and the firing voltage of a mixed gas is lower than that of a single gas such as He gas. The minimum sustain voltage and the maximum sustain voltage or firing voltage increases with decrease in the frequency. The effective wall capacitance increases as the discharge strength that is, the gap voltage between discharge electrodes increases.

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Effect of Discharge Gas on the Electrical Characteristics of the Glow Discharge Plasma for the Gas Chromatographic Detector (글로우방전 가스크로마토그라프 검출기에서 방전가스의 영향)

  • 박현미;강종성;김효진
    • YAKHAK HOEJI
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    • v.39 no.5
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    • pp.480-486
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    • 1995
  • The change in discharge current of a glow discharge has been shown the potential sensitive detector for gas chromatography. To investigate the effect of carrier gas on the electrical characteristics of the discharge and the peak response, the discharge pressure, gas flow rate, and discharge gap have been studied. The discharge gas included the Ar, He, and N$_{2}$. The gas flow rate has been found one of the important parameters to affect both the electrical characteristics and the peak response.

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Effects of Panel Temperature on the Discharge Characteristics of Micro Discharge Cells

  • Shim, Kyung-Ryeol;Park, Chung-Hoo;Lee, Ho-Jun
    • KIEE International Transactions on Electrophysics and Applications
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    • v.4C no.5
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    • pp.215-219
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    • 2004
  • The effects of ambient temperature on the discharge characteristics of Ne-Xe based micro discharge cells for ac-PDP (plasma display panel) have been studied. In ramp voltage driving, which is generally used as a reset method of PDP, two dissimilar modes of strong and weak discharge were found. As the interval between the former sustaining discharge and ramp voltage discharge becomes greater, the probability of a strong discharge increases. This suggests that a sufficient number of priming particles is necessary for initiating weak mode (Townsend discharge). It was discovered that under higher ambient temperatures, weak discharge occurs more frequently. The discharge time lag observed in square pulse driving of single cells becomes surprisingly smaller under higher ambient temperatures for the constant gas number density condition.

Prediction of electric dynamics of electric discharge machining using Plasma model (플라즈마 모델을 이용한 방전가공의 전기적 거동 예측)

  • Kim K.W.;Jeong Y.H.;Min B.K.;Lee S.J.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.10a
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    • pp.604-607
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    • 2005
  • In the electro-discharge machining the machining performance is closely related to the characteristics of discharge which can be identified from electrical behavior in gap between workpiece and electrode. Therefore, the accurate prediction of electrical behavior in electro-discharge machining (EDM) is useful to process control and optimization. However, any simulation model fur prediction of electrical behavior in EDM process has never been reported until now. In this study, a simulation model is developed to analyze the electrical behavior of electro-discharge plasma which significantly influences electrical behavior in EDM process. For the purpose of this the fundamentals of electro-discharge mechanism such as inception, propagation, formation of plasma channel and termination are investigated to accurately predict the cycle of discharge plasma in EDM. As a result, a mathematical model of electro-discharge plasma is constructed with considering the fundamentals of electro-discharge plasma. Consequently, it is demonstrated that the developed model can predict the electrical behavior of plasma such as electron density in various conditions.

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Effect of Self-Erase Discharge on the Luminous Efficacy of Long Gap AC PDPs

  • Kim, Tae-Jun;Jung, Jae-Chul;Jung, Hae-Yoon;Whang, Ki-Woong
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.585-588
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    • 2007
  • We studied the effect of self-erase discharge on the luminous efficacy of ac PDPs. We observed through discharge current analysis to confirm that the selferase discharge occurred mainly between sustain cathode and address electrode, which have an influence on the luminous efficacy. The amount and timing of the self-erase discharge was varied to observe its effect on the luminous efficacy. It has been found that the luminous efficacy could be improved by the self-erase discharge when it is adjusted to occur right before the main discharge in the small gap structure. In the long gap structure, on the contrary, the luminous efficacy could be increased when the self-erase discharge is suppressed. Also, various waveforms to control self-erase discharge are suggested and tested in the panel experiments.

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A study about diagnosis of PD signal using by Fuzzy algorithm (퍼지 알고리즘을 이용한 부분방전 신호의 진단에 관한 연구)

  • Kim Jinsu;Park Jaewan;Park Keon-Jun;Oh Sung-Kwun;Kim Yong K.
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2005.11a
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    • pp.440-443
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    • 2005
  • In this paper, we introduce about a new class to analysis of partial discharge signal based on Fuzzy model. We can early diagnose life of power cable through detection of partial discharge signal. However, partial discharge signal detector is difficult because of partial discharge signal is very non-linear. Also, it is very difficult work that separate partial discharge signal from noise. We constructed partial discharge accumulation detection system that use Labview for detection of non-linear partial discharge signal. And analyzed partial discharge signal that is detected by Labview system utilizing Fuzzy model.

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A Study on the Discharge Characteristics of Micro Dielectric Barrier Discharge Cells by Adding TiO2 or MgO Powder (TiO2 또는 MgO 첨가에 따른 마이크로 유전격벽방전 셀의 방전특성 연구)

  • Han, Chang-Wook;Wi, Sung-Suk;Lee, Don-Kyu
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.64 no.11
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    • pp.1587-1591
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    • 2015
  • For a higher definition discharge cell, the method of high speed addressing is necessary. In order to modify the surface charges, the liquefied $TiO_2$ or MgO powder is added on MgO layer in front glass and on the phosphor in rear glass in micro barrier discharge. Both the electro-optical properties and the discharge time lag characteristics are measured from 4 inch. test panel, such as the discharge voltage, current, luminance, luminous efficacy and discharge time lag. As the results, the statistic time lag is improved by about 40 %.

Properties of PD Pulses Accompanying with Bush-type Tree in LDPE (저밀도 폴리에틸렌에서 부시형 전기트리에 수반되는 부분방전 펄스의 특성)

  • 강성화;박영국;정수현;이광우;임기조
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.12
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    • pp.1055-1059
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    • 1998
  • The correlation between the propagation of electrical tree and distributions of partial discharge(PD) pulses accompanying with electrical tree of bush type in low density polyethylene were discussed. We measured the growth of electrical tree by using optical microscope and PD data simultaneously. The PD data detected and analyzed were PD magnitude, repetition rate, average discharge power, average phase angle, and $\psi$-q-n distribution pattern. The average discharge power and repetition rate of PD had good linear relation with area of tree. Repetition rate and peak discharge magnitude and width of discharge phase angle increased with the tree.

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A Basic Study on Electrical Discharge Machining (방전 가공의 기초적 연구)

  • 김해종;마대영;김상현
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1994.05a
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    • pp.42-45
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    • 1994
  • In this paper, we will report on the effect of the pointed end shape of an electrode, discharge energy, pulse width and discharge current on machining characteristics. The results obtained are as tollows: 1)As the discharge Energy increases, the diameter and the depth of the discharged crater becomes larger and deeper. 2) The discharge energy is not constant during discharge but varies depending on the pointed end shape of th8 electrode. 3) The shape of crater depends on the pulse width and discharge current.

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