• 제목/요약/키워드: Discharge current

검색결과 1,792건 처리시간 0.031초

금속결합제 연삭숫돌의 방전트루잉에서 기준전류와 절입깊이가 방전에너지에 미치는 영향 (Effect of Reference Current and Depth of Cut on Electro-Discharge Energy in Electro-Discharge Truing Process for Metal-Bonded Grinding Wheel)

  • 신건휘;곽태수;정명원;곽인실
    • 한국정밀공학회지
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    • 제33권6호
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    • pp.485-490
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    • 2016
  • This study focused on developing an electro-discharge truing method for the ELID grinding process using a metal-bonded grinding wheel. The truing process in grinding plays important roles in enhancing the quality of the ground surface. In this study, a reference current in the electro-discharge truing process was confirmed to be a viable solution for efficient truing through performance experiments. Current and voltage variation experiments were carried out and the variation output data were collected with a monitoring program to understand the electrodischarge phenomenon that occurs between metal-bonded grinding wheels and copper electrodes. The experimental results showed that as the reference current decreased, the average electro-discharge energy decreased. Therefore, the reference current can be used as an indicator to estimate the size of the gap between the truer and grinding wheel.

상용주파수 교류방전 $CO_2$ 레이저의 동작 특성 (A Study on the Operational Characteristics of $CO_2$ Laser Excited by 60Hz AC Discharges)

  • 이동훈;임규호;정현주;김희제;조정수
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제48권8호
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    • pp.587-590
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    • 1999
  • In this study, it is the purpose to develope a cheap and compact $CO_2$ laser and to apply 60 Hz AC discharges as a new exciting source. An axial and water cooledtype was adopted as the laser mode. The laser performance characteristics as various parameters, such as gas pressure and discharge current, have been investigated. And the laser output and the efficiency of DC and 60 Hz AC discharge-exciting type have been measured and compared for the different input powers at the static operational pressure. As a result, the case of 60 Hz AC discharge-exciting type, the laser oscillation began at the condition of operational pressure 6 Torr and discharge current 5 mA. A maximum laser output of about 32 W was obtained at an operational pressure of 18 Toorr and a discharge current of 30 mA. In addition, the laser output was saturated from an operational pressure of about 14 Torr and a discharge current of about 20 mA. In this $CO_2$ laser, the laser output of 60 Hz AC discharge-exciting type was slightly higher than that of DC discharge-exciting type. And the laser efficiency was about 10 to 13% for the various operational pressures and the discharge currents.

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EPR의 열화에 의한 충.방전 전류 특성에 관한 연구 (A Study on Properties of Charge & Discharge Current by Degrade in EPR)

  • 이성일
    • 한국전기전자재료학회논문지
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    • 제21권7호
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    • pp.679-685
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    • 2008
  • This paper describes the degraded properties of between the charge and discharge current for ${\gamma}$-ray irradiated in electric power cable rubbers using in nuclear power generating station. The charge and discharge current of degradation in EPR(Ethylene Propylene Rubber), which were irradiated with the radiant capacity of 0.033 Mrad/h, have been measured in order to investigate the influence of the atmosphere(in amount of reinforcing agent, moisture absorption and heat treatment) on electrical properties. When ${\gamma}$-ray were irradiated on the EPR with more reinforcing agent from 4 to 40 Phr, charge and discharge currents was increase due to the amount of reinforcing agent. It was verified that the discharging and charging currents irradiated by ${\gamma}$-ray were higher than those that was not irradiated. The amount of the degraded current was more after moisture absorption than before moisture absorption. The charge and discharge current after heat treatment was similar to that of before heat treatment and it was decreased with the time elapsed. As these properties related with ${\gamma}$-ray irradiation dose, it is suggested that these properties can be utilized as a index of irradiation degradation.

고온 초전도 퓨즈의 한류 및 방전 특성 (Current Limiting and Discharge Characteristics of High Tc Superconductive Fuse)

  • 최효상
    • 한국전기전자재료학회논문지
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    • 제17권6호
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    • pp.673-677
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    • 2004
  • We present the basic properties of a superconductive fuse (SF) based on YBCO/Au films. The SF consists of YBCO stripes covered with Au layers for current shunt. The fault current was limited to a designed value in less than 0.4 msec by resistance development in YBCO/Au upon quenching. This enabled the SF to transfer small fault power and the suppressed current was sustained for more than 0.5 msec while Au layer melting and arcing. The arcing time was less than 2.5 msec, that is short enough to do self-interruption. Under the source voltage of 100 $V_{rms}$, the longer the duration time of fault current was, the shorter its discharge time was. The duration time of fault current and its discharge time were reduced by increased voltages in the range of 200 - 300 $V_{rms}$. We thought that this was because the quench propagation was limited by local melting generated with higher voltage.age.

다중방전 경로를 이용한 편상접지체의 접지저항 및 전류특성 (Grounding Resistance and Current Characteristics of the Planar Earth Structure using Multiple Discharge Paths)

  • 김영선;김동민;이기식
    • 전기학회논문지
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    • 제65권9호
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    • pp.1564-1570
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    • 2016
  • This study proposes a newly modified form of existing ground electrodes in order to secure trust of grounding system for large current caused by a stroke of lightning. Proposed planar earth structure has a several needle electrodes around a circular rod and 4 plane electrodes in all directions. The plane electrodes are fused with the insulator on the linear rod, so that they're electrically isolated. The concept is to increase the discharge amount of earth structure using multiple discharge paths like needle and plane electrodes. To check the discharge efficiency of the suggested scheme, the discharge currents are compared with typically used two kinds of ground rods. To ensure accuracy in the measurement of the discharge current, the same material was used for the comparison model. Also, the ground resistance are simulated by CDEGS commercial software and the results are compared with measured data. Based on this kind of experimental study, the suggested ground rod can be used when designing a ground system or when constructing a ground system at the site.

글로우 방전을 이용한 기체크로마토그라피 검출기 (A Gas Chromatographic Detector using Glow Discharge)

  • 한종수;송승호
    • 대한화학회지
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    • 제35권4호
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    • pp.350-354
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    • 1991
  • 헬리움 흐름에서 글로우 방전을 이원화원으로 사용한 기체 크로마토그라피의 검출기 특성을 연구하였다. 방전전극 사이의 거리가 1 mm 일 때, 400 V/mm 의 전장의 세기 이상에서 10$_6$A 이상의 방전전류가 관찰되었다. 유기물의 검출에는 0.1~0.3 mA의 방전전류가 적당하였다. 순수한 헬리움의 흐름에서는 10 ml/min 이상의 유속에서 방전전류가 거의 일정하였으나, 0~30 ml/min 의 유속에서는 적은양의 유기물의 주입에 의해 방전이 쉽게 사라졌다. 여러 화합물에 따른 방전전류의 감소로부터 글로우 방전 이온화 기체크로마토그라피 검출기의 감도는 그 화합물의 분자량에 크게 영향받음을 알았다.

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AC PDP에서 2차원 수치해석을 이용한 Ramp Reset 구동파형에 따른 방전 특성 분석 (The Discharge Characteristic Analysis of a Ramp Reset Waveform Using a 2-Dimensional Numerical Simulation in AC PDP)

  • 박석재;최훈영;서정현;이석현
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제53권12호
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    • pp.606-615
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    • 2004
  • The discharge characteristics of a ramp reset waveform in the alternating current plasma display panel(ac PDP) were studied using a 2-dimensional numerical simulation. We analyzed the wall charge variation during the reset discharge, address discharge and sustain discharge adopting a ramp reset waveform. Then we investigated the principal parameters for a successful discharge. In this paper, we suggest a new parameter, printing particles' density and its effects on the stability of the ramp discharge. The maximum current flows of the three electrodes during the ramp reset period were decreased with the increase in the priming particles's density which was explained with the wall charge characteristics and the current flow characteristics obtained by a 2-D simulation.

미소 방전존재시의 ${SF}_{6}$에 대한 교류절연 파괴 특성 (A.C Breakdown Characteristics in ${SF}_{6}$ in the Presence of A Small Discharge)

  • 이광식;이동인;김인식
    • 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.

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Salt fog 시험에서 silicone rubber에서 발생하는 방전 전류의 특성 (The surface discharge performance of silicone rubber in the Salt fog test)

  • 강성화;박영국;이광우;김완수;이용회
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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    • pp.565-569
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    • 1999
  • In these days, the silicone insulators have been increasingly studied and applied for outdoor insulators because it has superior characteristics than porcelain and glass insulators, which have been used for outdoor insulators. First of all, The excellent performance of the silicone rubber in polluted and wet conditions is attributed to the ability of the material to maintain the hydrophobicity of the surface in the presence of severe contamination and wet conditions. This is because of the presence of low molecular weight mobile fluid in the silicone rubber which diffuses to the surface and to above the contamination layer. But, the leakage current and some surface discharge occurs on surface of the composite polymeric insulation materials when the insulator is used for a long time with severe contaminative condition and it can lead the contamination flashover. So the leakage current and the discharge current are important to estimate the condition of the silicone rubber surface. In this paper, the average leakage current, the relation of surface discharge current and phase angle were study to investigate electrical conduction of silicone rubber surface with the salt fog condition.

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핀이 부착된 와이어형 방전극의 형상에 따른 코로나 방전특성에 대한 연구 (Experimental Study on the Corona Discharge Characteristics of the Pin-plate Electrode Geometries)

  • 정성일;이재근;정동규;안영철
    • 대한기계학회논문집B
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    • 제30권2호
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    • pp.95-100
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    • 2006
  • Electrostatic precipitators(EPs) have low pressure drop and high dust collection efficiency and are widely used for industrial dust collectors. The current-voltage characteristics, which are important to maintain high dust collection efficiency, depend on several factor: discharge electrode shape, gas flow property, dust loading etc. In this study, experiments are performed to investigate the current-voltage characteristics of the corona discharge of various electrode geometries and an empirical model is proposed to predict current-voltage characteristics of the corona discharge. The corona onset voltage correction coefficient$(\alpha)$ and the geometry correction coefficient$(k_g)$ are used to the conventional equation for wire-plate type discharge electrode. The corona onset voltages are -6.3kV and almost constant when the numbers of discharge pins are varied from 3 to 9. The length of discharge pins has very sensitive effects on the corona onset voltage. They are increased from -6.3 to -7.8kV when the discharge pin length are 8.5 and 4.5mm, respectively. The empirical model shows good agreement with experimental results and can predict the effects of discharge pin length and number.