• Title/Summary/Keyword: Discharge current

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1-Dimensional Simulation of the Corona Discharge using Fluid Method (유체법을 이용한 코로나 방전의 1차원 수치해석)

  • 이용신;심재학;고광철;강형부
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.04a
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    • pp.172-176
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    • 1997
  • It is likely that the corona discharge appears due to the motion and the multiplication of electron and ion under the nonuniform electric field. Because the motion and the multiplication of electron and ion are the function of electric field, for the simulation of the corona discharge, we have to calculate the electric field, before the calculation of the motion and the multiplication of electron and ion. In this paper, the electric field is calculated on the assumption that the gap between a hyperboloidal needle and a plane is 1-dimension, and the motion and the multiplication of electron and ion are determined by Flux-Corrected Transport method. For this purpose, we solve the electron and ion continuity equation together with Poisson equation. We calculated the current density and the electron and ion density distributions between electrodes as well as electric field distortion due to the space charge assuming that the discharge channel radius is 100${\mu}{\textrm}{m}$. In this simulation, it is found that the current density has one peak as observed by experiment, and electric field distortion is important to the formation and the stability of the corona discharge.

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Effects of Nitrogen Gas Ratio on Nitride Layer and Microhardness of Tool Steel(SKH51) in Plasma Nitriding (플라즈마질화시 방전가스중 질소가스의 비율이 공구강(SKH51)의 질화층 및 미소경도에 미치는 영향)

  • Kim, Deok-Jae;Lee, Hae-Ryong;Gwak, Jong-Gu;Jeong, U-Chang;Jo, Yeong-Rae
    • Korean Journal of Materials Research
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    • v.12 no.6
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    • pp.447-451
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    • 2002
  • Pulsed DC-plasma nitriding has been applied to form nitride layer having only a diffusion layer. The discharge current with the variation of discharge gases is proportional to the intensity of $N_2^+$ peak in optical emission spectroscopy during the plasma nitriding. The discharge current, microhardness in surface of substrate and depth of nitride layer increased with the ratio of $N_2\;to\;H_2$ gas in discharge gases. When the ratio of $N_2\;to\;H_2$ is lower than 60% in the discharge gases, high microhardness value of 1100Hv nitride layer which contains no compound layer has been formed.

Electrochemical Characteristics of $LiMn_{2}O_{4}$/Lithium Cells in Organic Electrolyte (유기전해액 $LiMn_{2}O_{4}$/Lithium 전지의 전기화학적 특성)

  • 임정환;도칠훈;문성인;윤문수
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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    • pp.371-374
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    • 2000
  • The electrochemical properties of LiM $n_2$ $O_4$as a cathode and an anode for the lithium secondary battery were evaluated. When LiM $n_2$ $O_4$ material was used as the cathode with the current collector of aluminum, the 1st specific capacity and the 1st Ah efficiency in LiM $n_2$ $O_4$/lithium cell were 123 mAh/g and 91.7%, respectively The anodic properties of LiM $n_2$ $O_4$ material was also evaluated in the LiM $n_2$ $O_4$/1ithium cell with the current collector of copper. It showed that the LiM $n_2$ $O_4$ was useful as the anode for the lithium secondary battery. During the 1st discharge, a potential plateau was observed at the potential of 0.3 $V_{Li}$ Li+/. The 1st specific charge capacity and the 1st specific discharge capacity were 790 mAh/s and 362 mAh/g, respectively. Therefore, the 1st Ah efficiency was 46%. The discharge capacity was gradually faded with the charge-discharge cycling to about 50th cycles. Thereafter, the discharge capacity was stabilized to about 110 mAh/g.

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Analysis on DC Glow Discharge Properties of Ar Gas at the Atmosphere Pressure (대기압 Ar 가스의 직류 글로우 방전 특성분석)

  • So, Soon-Youl
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.59 no.4
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    • pp.417-422
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    • 2010
  • Atmosphere Plasma of Gas Discharge (APGD) has been used in plasma sources for material processing such as etching, deposition, surface modification and so on due to having no thermal damages. The APGD researches on AC source with high frequency have been mainly processed. However, DC APGD studies have been not. In order to understand APGD further, it is necessary to study on fundamental properties of DC APGD. In this paper, we developed a one-dimensional fluid simulation model with capacitively coupled plasma chamber at the atmosphere pressure (760 [Torr]). Nine kinds of Ar discharge particles such as electron (e), positive ions ($Ar^+$, $Ar_2^+$) and neutral particles ($Ar_m^*$, $Ar_r^*$, $Ar_h^*$, $Ar_2^*$(1), $Ar_2^*$(3) and Ar gas) are considered in the computation. The simulation was worked at the current range of 1~15 [mA]. The characteristics of voltage-current were calculated and the structure of Joule heating were discussed. The spatial distributions of Ar DC APGD and the mechanism of power consumption were also investigated.

RF Glow Discharge Characteristics of Argon at Low Gas Pressure (저기압하의 아르곤 가스의 RF 글로우 방전특성)

  • Kwak, D.J.;Kim, D.H.;Park, C.H.
    • Proceedings of the KIEE Conference
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    • 1995.07c
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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.

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Corona discharge characteristics of ceramic discharge plate (세라믹 방전판의 코로나 방전 특성)

  • 최규남
    • Journal of the Korean Institute of Telematics and Electronics T
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    • v.36T no.3
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    • pp.72-78
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    • 1999
  • The frequency characteristics of surface corona discharge from the electrodes on the ceramic substrate ozonator were investigated. The frequency characteristics of dark current were compared with that of corona discharge. Switching frequency which was the fraction of resonant frequency was found to be effective for corona discharge. This is regarded to distort the electric field distribution on the discharge plate which is essential for corona discharge. The measurement showed the efficiency of 28mg/W ozone generation when the switching frequency was 1/5 of the resonant frequency.

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Silent Discharge and Ozone Generation Characteristic of $Al_2O_3$ (아루미나 방전관의 무성방전 및 오존발생특성)

  • Kim, Hag-Gyu;Kwak, Dong-Joo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07b
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    • pp.908-911
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    • 2002
  • Recently deep interests and attraction have been paid on the generation of ozone, which is widely used to remove bed smell and to clear water. In this paper the silent discharge and ozone generation characteristics of various typed discharge chambers were investigated experimentally. Dielectric of $Al_2O_3$ was embedded in the cylindrical type of discharge chamber to improve the ozone generation rate and to stabilize the silent discharge mode of operation. Discharge current and ozone concentration depend strongly on the applied voltage and frequency.

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Characteristics of RC circuit with Transistor in Micro-EDM (트랜지스터 부착 RC 방전회로의 마이크로 방전가공 특성)

  • 조필주;이상민;최덕기;주종남
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.10a
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    • pp.235-240
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    • 2002
  • In micro-EBM, it is well blown that RC circuit is suitable for discharge circuit because of its low pulse width and relatively high peak current. To increase machining speed without changing unit discharge energy, charge resistance should be decreased. But, if very low, continuous (or normal) arc discharge occurs, then increases electrode wear and reduces machining speed remarkably. In this paper, RC circuit with transistor is used to micro-EDM. Experimental results show that RC circuit with transistor can cut off continuous (or normal) arc discharge effectively if duty factor and switching period of transistor are set up optimally. Through experiments with varying charge resistance, it can be known that RC circuit with transistor has about two times faster machining speed than that of RC circuit. Especially, it has prominent rise-effect of machining speed in low unit discharge energy, so that a high-quality and high-speed micro-EDM can be realized through RC circuit with transistor.

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A Novel Battery Charge/Discharge System with Zero Voltage Discharge Function (영전압 방전 기능을 갖는 새로운 배터리 충방전시스템)

  • Nguyen, Quang Manh;Choi, Woojin
    • Proceedings of the KIPE Conference
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    • 2013.07a
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    • pp.169-170
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    • 2013
  • One important test for formation and grading of the lithium-ion battery is to confirm the performance of the battery while discharging battery down to zero volts. In this paper, a novel charge/discharge converter with zero-voltage discharge function is proposed. The proposed converter is able to discharge the battery until the voltage reaches to zero volts. The phase-shifted full bridge method is used to charge the battery and the current-fed push-pull method with bidirectional switches is used for the discharge. The ZVS turn-on is achieved in the charge operation and the ZVS turn-off in the discharge operation. The performance of the system is verified by the experiments using lithium-ion batteries.

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Discharge characteristics of FFL as applied voltage variation (인가 전압의 변화에 따른 FFL(Flat Fluorescent Lamp)의 방전특성)

  • 윤성현;박철현;조민정;임민수;권순석;임기조
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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    • pp.379-382
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    • 2000
  • The characteristics of Xe discharge lamp(Mercuryless lamp) are described in this paper. In this paper, FFL is operated by sine wave and pulsed source. We apply V-Q Lissajous' figure for the discharge measurements of FFL which has the electrodes covered with dielectric. When FFL is operated by sine wave source, the characteristics are similar to DBD(Dielectric Barrier Discharge) and SD(Silent Discharge). And we compared the characteristics of FFL which is operated with sine wave and pulsed discharge by using V-Q Lissajous' figure method. When FFL is operated with pulsed, the discharge current flows after the applied voltage is risen. As the duty ratio increases the electric field becomes strong and much more xenon ions are produced. And the number of metastable xenon atoms seem to increase, therefore, the phosphor radiation after the cut off of voltage increases compared with the first peak of radiation. Consequently, the 172㎚ radiation becomes strong as the duty ratio increases.

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