• 제목/요약/키워드: gap distance

검색결과 584건 처리시간 0.025초

가공(架空)전력선을 모의(模擬)한 공기 갭에서 교류 및 직류 섬락특성에 미치는 연소화염의 영향 (The Influence of Combustion Flame on AC and DC Flashover Characteristics in the Air-Gaps Simulated Overhead Power Lines)

  • 김인식
    • 조명전기설비학회논문지
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    • 제24권5호
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    • pp.152-159
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    • 2010
  • 가공전력선이 통과하는 지역에서 발생된 연소화염은 계통 섬락사고의 원인이 되고 있다. 본 논문에서는 연소화염에 의한 전력선의 절연내력 저하특성과 화염의 형상변화를 알아보기 위해, 직류 및 교류 전압 인가시 전력선을 모의한 대기압 공기 갭에 대한 섬락특성과 화염의 소화특성을 조사하였다. 실험 결과, 화염에 의한 섬락현상은 비교적 작은 갭에서 발생되었으며, 수평배치형 침대침 갭에서 교류 섬락전압의 상대값은 평균 37.3[%]인 것으로 나타나 화염이 없는 경우에 비해 크게 저하하였다. 갭 길이가 증가함에 따라 전극간 섬락이 발생되기 전에 침전극로부터 발생된 코로나풍에 의해 화염은 소화되는 현상이 나타났다.

Capacitive Switching Antenna의 최적 에너지 전달에 관한 연구 (A Study on Optimizing Energy Transfer of Capacitive Switching Antenna)

  • 김진만;방정주;허창수
    • 전기학회논문지
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    • 제62권2호
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    • pp.232-238
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    • 2013
  • In this paper we describe the maximum energy transfer of CSA(Capacitive Switching Antenna). CSA which is radiated antenna system contain energy storage and switch, antenna needs to high voltage source for electrical field radiation experiment. In this experiment we employed Marx generator as a charging source. CSA can radiate electrical field more efficiently by varying antenna capacitance. The electromagnetic generation system which was using CSA has some advantages which are more simple and more effective compared to exist system. We evaluated the performance of electromagnetic wave generating system using CSA. As a result UWB gain of system is 0.47, It is higher level than exist system is 0.3. Radiated electrical field strength at 1m is 70kV/m. It is measured by D-dot sensor and gap distance is 20mm. Center frequency of CSA is approximately 25MHz. When vary the antenna gap distance from 50mm to 20mm, we can find the radiation field strength is decrease and antenna center frequency is increased. We also simulated the energy transfer efficiency to compare with experiment result. Consequentially, CSA needs to appropriate capacitance which is similar value from marx generator for maximum energy transfer, and gap is less than 1mm to increase the CSA capacitance.

고체 유전율 측정용 cell의 불확도 분석과 보상 (Uncertainty and Compensation on the cell for Measurement of the Solid Permittivity Materials)

  • 김한준;강전홍;유광민;이세현;구경완;한상옥
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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    • pp.482-483
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    • 2007
  • For measurement of dielectric constants, the commercial parallel plate electrodes system with guard-ring electrode have been widely used up to now. The capacitance derived from the parallel plate electrodes capacitor with guard-ring electrode is calculated by the equation of ($C={\epsilon}\;{\cdot}\;\frac{area\;of\;electrod}{distance\;between\;electrodes}$). Therefore, in parallel plate electrode capacitor, the diameter of the guarded electrode, the gap size between guarded electrode and guard ring, and distance between two active electrode should be measured precisely to calculate dielectric constants from the measured capacitance. Consequently their mechanical measurement uncertainties are directly contributed. Especially the air-gap between the electrodes and dielectric specimen at the system must be existed and the measurement error derived from the air-gap is impossible to evaluate as measurement uncertainties. In this study, we analyze the uncertainty of the commercial dielectric constant test cell using 3 kinds CRMs.

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GTA-GMA 하이브리드공정에 따른 자동차용 아연도금강판의 용접부 기공감소 (II) - 하이브리드공정 적용 결과 (Porosity Reduction during Gas Tungsten Arc-Gas Metal Arc Hybrid Welding of Zinc Coated Steel Sheets (II) - Hybrid Welding Results)

  • 안영남;김철희
    • Journal of Welding and Joining
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    • 제34권4호
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    • pp.48-54
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    • 2016
  • The use of Zn coated steel has increased in the automotive industry due to its excellent corrosion resistance. Conventionally the BIW(body-in-white) structure and the hang-on parts have been made of Zn coated steel and more recently Zn coated steel began to be applied in the chassis parts. During gas metal arc (GMA) welding of the chassis part, lap fillet joint used to be adopted but spatter generation and porosities are most important concerns. In the industrial applications, an intentional joint gap was made to avoid the weld defects but it is not easy to control the size of joint gap. In this research, gas tungsten arc (GTA) is combined with GMA welding where GTA precedes GMA. As pulsed arc was adopted as GMA, GTA was oscillated along the longitudinal direction by pulsing GMA, but the arc oscillation did not disturb the molten droplet transfer of GMA welding. By increasing the distance between GTA and GMA, the length of weld pool increased and porosity could be reduced. Moreover porosity in the welds was fully removed when the distance between two arcs was 15 mm.

2차원 시뮬레이션을 이용한 전극 간격에 따른 방전셀 내부의 특성 연구 (A Study on the Characteristics on a Discharge Cell by the Electrode Gap Using 2-D Simulation)

  • 이돈규
    • 전기전자학회논문지
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    • 제23권2호
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    • pp.524-528
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    • 2019
  • 다양한 종류의 방전 셀이 존재하고 있지만, 공통적으로 모든 방전 셀은 보다 낮은 구동 전압에서 보다 높은 효율 특성을 가지는 것을 우선적인 목표로 한다. 이러한 특성 개선을 위해 방전셀 내부의 방전 경로를 길게 하거나 구동 가스의 성분을 변화시키는 연구가 많이 이루어진다. 본 논문에서는 2차원 유체 시뮬레이션을 이용하여 방전전극 사이의 간격에 따른 방전전압 (개시전압 및 유지전압) 및 휘도와 효율의 변화를 계산하였다. 또한, 다양한 하전입자와 여기입자 및 파장별 진공자외선의 변화를 살펴보고 휘도와 효율의 원인을 연구해 보았다.

연속 slot-die 코팅법을 이용한 TPD 유기 정공수송층의 코팅 특성 분석 (Coating Properties of a TPD Organic Hole-transporting Layer Deposited using a Continuous slot-die Coating Method)

  • 정국채;김영국;최철진
    • 대한금속재료학회지
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    • 제48권4호
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    • pp.363-368
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    • 2010
  • N,N'-diphenyl-N,N'-bis(3-methylphenyl)1-1' biphenyl-4,4'-diamine (TPD) hole-transporting layers were deposited using a continuous slot-die coating method on ITO/PET flexible substrates. It is crucial that the substrates have a very smooth surface with a RMS roughness of less than 2 nm for the deposition of semiconductor nanocrystals or Quantum Dots. The parameters of the slot-die coating, including the solution concentration of the TPD, the gap between the slot-die and the substrates, and the coating speed were controlled in these experiments. To obtain full coverage of the TPD films on the ITO/PET substrates (40 mm wide and several meters long), the injection rates of the TPD solution were increased proportional to the coating speed of the flexible substrates. Additionally, the injection rates must be increased as the gap distance changes from 400 to 600 ${\mu}m$ at the same coating speed. A RMS surface roughness of less than 2 nm was obtained, in contrast to bare ITO/PET substrates, at 13 nm, as the coating speed and gap distance increased.

쌍방향 시동방식의 고속투입스위치 개발 (Development of the Spark-gap Switch with Dual Trigger System)

  • 김맹현;서윤택;박승재;박병락;고의석
    • 대한전기학회논문지:전력기술부문A
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    • 제49권7호
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    • pp.359-364
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    • 2000
  • This paper is introducing a newly developed spark-gap switch with dual trigger system, into which the current from the voltage source is injected along with the test sequence during the synthetic testing of high voltage circuit-breaker. The currently-used spark gap switch is narrow in operating range due to the use of the method of triggering energy being injected by single way. As a result, the frequent happening of misoperation has greatly reduced the test quality and test efficiency and has required the cost of maintenance excessively. In this study, accordingly, in order to basically remove these problems, another triggering system is installed to the opposite direction on the existing triggering system; attaching the same time and the same rising time of pulse wave as on the existing system, so that at a comparatively trigger gap distance from the main electrode(the gap can be operated at 60% of self-break voltage, while at 80% in the current system), the main electrode has been enabled to be closed by the development of spark gap switch with dual trigger system.

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자기부상시스템에서 레일 이음매 통과시 공극 처리방법 (Air-gap Signal Treatment at rail-joint in Maglev System)

  • 성호경;조정민;이종무;배덕권;김봉섭;김동성;신병천
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.310-312
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    • 2006
  • Maglev using EMS becomes unstable by unexpected big air-gap disturbance. The main causes of the unexpected air-gap disturbance are step-wise rail joint and large distance between rail splices. For the stable operation of the Maglev, the conventional system uses the threshold method, which selects one gap sensor among two gap sensors installed on the magnet to read the gap between magnet and guide rail. But the threshold method with a wide bandwidth makes the discontinuous air-gap signal at the rail joints because of the offset in air gap sensors and/or the step-wise rail joins. Further more, in the case of the one with a narrow bend-width, it makes Maglev system unstable because of frequent alternation. In this paper, a new method using fuzzy rule to reduce air-gap disturbances proposed to improve the stability of Maglev system. It treats the air-gap signal from dual gap sensors effectively to make continuous signal without air gap disturbance. Simulation and experiment results proved that the proposed scheme was effective to reduce air-gap disturbance from dual gap sensors in rail joints.

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자기장 센서를 이용한 갭간격이 없는 박판 맞대기 용접부의 용접선 추적 장치 (Joint tracking system for butt joint welding process using eddy current sensors with the condition of no gap distance)

  • 김영선;조형석
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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    • pp.836-839
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    • 1997
  • In recent years, much progress has been made in the automation of welding coped with a variety of highly flexible sensors. Among these sensors, only the eddy current sensor can detect the center location of the butt joint whose gap distance is zero. Thus, in this study the eddy current sensor is used to develop a robust and useful joint tracking system. The developed system is tested to qualify the performance of the system and seam tracking algorithm is proposed and two simulation are executed to show the performance of the proposed tracking algorithm.

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저항형 고온초전도 한류기용 절연체의 절연 특성 (Breakdown Characteristics of Insulators for a Resistor Type HTS Fault Current Limiter)

  • 백승명;류엔반둥;김상현
    • 한국초전도ㆍ저온공학회논문지
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    • 제6권1호
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    • pp.48-52
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    • 2004
  • Breakdown characteristics of insulator-liquid nitrogen ($LN_2$) composite insulation for resistor type High $T_c$/ superconducting fault current limiter (HTSFCL) under ac and impulse voltage in $LN_2$ has been studied using model electrode systems. Electrodes for model electrode systems were made of SUS 304 contacted fiberglass reinforced plastic (FRP) and Au coated sapphire. The breakdown characteristics of model electrode systems were investigated experimentally for FRP thickness ranging from 1 mm to 5 mm. surface distance ranging from 2.5 mm to 7 mm and electrode gap ranging from 1 to 5 mm. The experimental data suggested that the breakdown voltage of model electrode systems in $LN_2$ is highly dependent on the surface distance, electrode gap as well as on the FRP thickness. Also, we had observed discharge traces and puncture due to high-voltage 60-Hz AC stress.