• 제목/요약/키워드: over current characteristics

검색결과 1,157건 처리시간 0.029초

금속 절연 초전도 코일의 과전류 특성 해석 (Analysis on the over current characteristics of metal insulated HTS coil)

  • 조전욱;심기덕
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2015년도 제46회 하계학술대회
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    • pp.1110-1111
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    • 2015
  • 초전도 코일의 안정성(stability)을 향상시키기 방법으로 초전도 자석의 턴(turn) 사이의 절연을 없애는 무절연 코일(no-insulation coil) 및 금속 테이프를 같이 권선하는 금속절연 코일(metal insulation coil)이 제안되어 활발히 연구되고 있다. 본 논문에서는 고온초전도 코일의 열적, 전기적 메카니즘을 분석하기 위한 FEM 모델을 제시하고, 이를 사용하여 �치 시 고온 초전도 코일의 안정성 향상 정도를 해석한다.

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전기광학변환소자로서의 결정과 그 응용 - 학술강연회초록

  • Naomi Furuya
    • 전기의세계
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    • 제22권3호
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    • pp.79-80
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    • 1973
  • This is the abstract of lecture on Electro-optic characteristics of D-KDP crystal and its application for high speed shutter made by Dr. Naomi Furuya; The professor of Yamanashi University in Kofu Japan on March 31, 1973 for KEEI in the auditorium of Korea Electric Company. His lecture is listened by KEEI members that KDP Z-cut crystal can be utilized as a high speed shutter of 10$^{-6}$ second, combining special camera and 2-3KV electrical impulse generator and also recording slide photographs on tungoten lamp crystal voltage and melting fuse phenomena due to over-current taken by this special equipment had been demonstrated.

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특별고압 전선로에 대한 인체접근한계의 이론적연구 (A Study on the Theoretical Analysis of Human Body Approximation to Special High Voltage Eletric Lines)

  • 김상렬;김찬오;이재인
    • 한국안전학회지
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    • 제5권3호
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    • pp.44-50
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    • 1990
  • This study is conducted to examine the theoretical background of characteristics for electric shock encountered in special high-voltage electric lines among the accidents of electric shock, and to calculate applied current to human body and field strength over the head by means of numerical anaysis through FEM(Finite Element Method), and to make clear the hazard level to the human body, and to establish the approach limit distance of human body to the electric lines, which could be applied to the safety standard while working in the vicinity of special high-voltage electric lines.

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철도운임체계 개선에 관한 연구 (The Study on railroad fare system improvement)

  • 권용장;정병현
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2000년도 춘계학술대회 논문집
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    • pp.32-42
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    • 2000
  • In this paper, we outlines the basic pricing rules that developed over the years, and illustrates how these rules apply in practice using railway fare, price discrimination in railway travel. we review the problems of rail fare system reflecting the market fare decision and consider fare decision structure and relative fare comparison with other modes of transportation. Specifically, we focus on tile effect of tile “fare varying system with distance”, using the characteristics of long distance transportation modes. And set up the framework for reasonable fare decision under the current circumstances.

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Load insensitive DC Chopper의 특성해석에 관한 연구 (A Study on the Analysis of the Load Insensitive DC Chopper)

  • 원종수;박상율
    • 전기의세계
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    • 제28권1호
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    • pp.67-72
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    • 1979
  • The most difficult problem encountered in the DC Chopper is the improvement in it's output waveforms and the commutation failure. Thus, this paper deals with the Load Insensitive DC Chopper that produces a quasi-pure square wave over the entire load range, and doesn't fail the commutation. The authors compared voltage and current waveforms from the laboratory model with those from the computer simulation, and it's characteristics is discussed.

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Photonic Quasi-crystal Fiber for Orbital Angular Momentum Modes with Ultra-flat Dispersion

  • Kim, Myunghwan;Kim, Soeun
    • Current Optics and Photonics
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    • 제3권4호
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    • pp.298-303
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    • 2019
  • We propose a photonic quasi-crystal fiber (PQF) for supporting up to 14 orbital angular momentum (OAM) modes with low and ultra-flat dispersion characteristics over the C+L bands. The designed PQF which consists of a large hollow center and quasi structural small air holes in the clad region exhibits low confinement losses and a large effective index separation (>$10^{-4}$) between the vector modes. This proposed fiber could potentially be exploited for mode division multiplexing and other OAM mode applications in fibers.

정류성 접합에 의한 광다이오드의 특성 개선 (The Characteristic Improvement of Photodiode by Schottky Contact)

  • 허창우
    • 한국정보통신학회논문지
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    • 제8권7호
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    • pp.1448-1452
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    • 2004
  • 비정질실리콘은 빛을 받으면 자유전자와 자유정공이 무수히 발생하여 전류 또는 전압의 형태로 나타나는 광전변환 재료이다. 이를 광다이오드로 사용하기 위해서는 금속 박막(Thin film)과 결합하여 쇼트키 다이오드로 만드는 기술이 효과적이다. 본 연구에서는 광다이오드의 신뢰성 및 특성을 개선하기 위하여 크롬실리사이드를 기존의 방식과 달리 하부 전극으로 크롬금속 박막을 증착한 후 그 위에 사일렌(SiH4)가스를 사용해서 PECVD (Plasma Enhanced Chemical Vapor Deposition) 진공 증착장비로 최적의 비정질실리콘 박막을 얇게 (100$\AA$) 만들어 열처리를 통하여 크롬실리사이드 박막을 형성 한 후 광다이오드 소자를 제조한다. 이렇게 형성된 크롬실리사이드 광 다이오드를 사용하여 암전류와 광전류를 측정찬 결과 기존의 방식보다 우수한 성능이 나타났고, 공정도 단순화 할 수 있었으며 그리고 신뢰성도 개선되었다.

조기은퇴남성의 주관적 삶의 만족도에 미치는 영향요인 분석 (The Factors Affecting Early Retired Men's Subjective Life Satisfaction)

  • 김지경;송현주
    • 가정과삶의질연구
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    • 제27권3호
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    • pp.31-43
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    • 2009
  • Using the first wave of KLoSA(Korean Longitudinal Study of Ageing) beta version, this study analyzed factors affecting early retired men's subjective life satisfaction through Binary Logit and Multiple Regression. Total 552 men were selected as a sample. The main results of empirical analysis in this study were as follows: The retirement reason(health-) and monthly household income(+) affected whether they were satisfied with the retirement life or not and subjective life satisfaction over all. Especially, the retirement reason(health-) had a stronger effect on whether early retired min were satisfied with the retirement life or not and their subjective life satisfaction than monthly household income revealed significant variable in previous studies. This result represents that the retiree's life satisfaction analysis model must include retiree's characteristics at the time of retirement as well as retiree's current status characteristics or socio-economic characteristics.

The Starting Characteristics Improvement of Single-Phase Induction Motor Reducing Over Current

  • 백형래;오금곤;조금배;박수강;임양수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 하계학술대회 논문집 A
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    • pp.531-533
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    • 1996
  • The most common method of the single phase induction motor(SPIM) is to install a starting condenser and a centrifugal switch in series with the auxiliary winding. Even though this capacitor start method is embodied simply, it is feasible because of motor failure from malfunction of the centrifugal switch and the starting condenser. Moreover, it is hard to improve the performance characteristics of the SPIM. In this paper, the voltage and phase angle sequence, control strategy of the auxiliary winding of the SFIM is employed to eliminate the centrifugal switch and the starting condenser. The proposed control system is superior to a conventional system in the starting performance of SPIM. Finally, the improved starting characteristics of the SPIM is obtained with this strategy through simulation and experimental results.

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플라즈마 응용을 위한 위상제어 정류기의 과부하 특성해석 (Overload Characteristics Analysis of Phase Controlled Rectifier for Plasma Application)

  • 노의철;정규범;김용진;최정완
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 1996년도 추계학술발표회논문집
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    • pp.104-108
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    • 1996
  • This paper deals with the design considerations and characteristics analysis of a SCR rectifier in pulsed over load operation. The Pulse repetition rate is one every 150 seconds and each current pulse width is 10 seconds. Therefore the characteristics of the transformer and SCR rectifier which consist the pulsed DC power supply are different from those of the conventional AC/DC power converters having continuous load. The variations of the DC output voltage drop, PF and THD versus the %Z of the transformer is analyzed through simulations and the experimental results thought to be useful in design high power pulsed DC power suppler.

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