• 제목/요약/키워드: Superconducting coil

검색결과 405건 처리시간 0.029초

전력용 고온초전도 코일 모의전극계에서의 기포거동에 관한 연구 (Study on Bubble Behavior with the Simulated Electrode System of High Temperature Superconducting Coils for Electric Power System)

  • 석복렬;김종구
    • 한국초전도ㆍ저온공학회논문지
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    • 제3권1호
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    • pp.16-21
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    • 2001
  • Bubble behavior is studied with an electrode system which consists of coaxial spiral coil-to-cylindrical electrode with an insulation barrier and spacers and is immersed in liquid nitrogen for simulation of insulation environments in high temperature superconducting(HTS) coils The results show that the bubble behavior Is affected severely by electric field: (1) under low applied voltage bubbles rise by buoyancy, but at higher applied voltage they are trapped in a lower electric field region below the coil electrode, and (2) the trapped bubble flows along the downside of coil electrode if no obstruction is in a groove between coil turns. but it splashes out of the groove after its growing if the obstruction such as spacer-exists.

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Pancake coil형 고온초전도 기기의 응용을 위한 극저온 냉매의 절연파괴 특성 (Breakdown Properties of Cryogenic Coolant for Pancake Coil Type High $T_{c}$ Superconducting Equipment)

  • 백승명;정종만;이진호;김상현
    • 한국초전도저온공학회:학술대회논문집
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    • 한국초전도저온공학회 2002년도 학술대회 논문집
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    • pp.185-188
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    • 2002
  • In the design of superconducting power equipments such as transformer, cable and fault current limit, knowledge of the dielectric behavior of both liquid and gaseous at very low temperatures is very importance. Especially, Electrical properties of liquid nitrogen($LN_{2}$) and gaseous nitrogen($GN_{2}$) have become of great interest again since the discovery of high temperature superconductors. However, many sources of $LN_{2}$and $GN_{2}$ problems in the test of pancake coil model arising form the deficiency of insulation data. Therefore, this paper describes the results of an experimental study on the ac breakdown voltage($V_{B}$) properties of $LN_2$ and Air under the electrode of simulated HTS pancake coil. The ac breakdown voltage of $GN_{2}$ have been measured by pancake coil-pancake coil gaps over the temperature range of 293 K to 77 K.

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$\mu$ SMES 마그네트용 모델 코일의 ?치 특성 (Quench Characteristic of the Model Coil for a $\mu$ SMES Magnet)

  • 김해종;성기철;조전욱;김석환;이언용;권영길;류강식;류경우
    • 한국초전도ㆍ저온공학회논문지
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    • 제3권2호
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    • pp.5-9
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    • 2001
  • For the development of a small-sized superconducting magnetic energy storage($\mu$SMES) system we designed, fabricated and tested a model coil consisting of five coils with different features. e.g. winding tensions. bore diameters and materials. cooling channels. The results show that even in the highly pre-stressed small coil the quench currents of the coils are degraded to about 70% of their coils critical current. The quench currents of the coils with natrow cooling channels are two times as high as that of the coil without spacers. The test results also indicate that the usual training effect depends on the winding tensions of the coils according to materials of the bobbin.

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6.6kV급 고온초전도 한류기용 HTS 코일의 절연 설계 및 시험 (Insulation Design and Testing of HTS coil for 6.6 kV Class HTSFCL)

  • 백승명;정종만;곽동순;류엔반둥;김상현
    • 한국초전도저온공학회:학술대회논문집
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    • 한국초전도저온공학회 2003년도 추계학술대회 논문집
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    • pp.263-268
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    • 2003
  • The Electrical insulation design and testing of high temperature superconducting (HTS) coil for high temperature superconducting fault current limiter (HTSFCL) has been performed. Electrical insulating factors of HTS coil for HTSFCL are turn-to-turn, layer-to-layer. The electrical insulation of turn-to-turn depends on surface length, and the electrical insulation of layer-to-layer depends on surface length and breakdown strength of L$N_2$. Therefore, two basic characteristics of breakdown and flashover voltage were experimentally investigated to design electrical insulation for 6.6㎸ Class HTSFCL. We used Weibull distribution to set electric field strength for insulation design. And mini-model HTS coil for HTSFCL was designed by using Weibull distribution and was manufactured to investigate breakdown characteristics. The mini-model HTS coil had passed in AC and Impulse withstand test.

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음향방출기법을 이용한 극저온 환경하에서 초전도 계자코일의 퀀칭탐지 적용에 관한 연구 (Application of Acoustic Emission Technique for On-Line Monitoring of Quench in Racetrack Superconducting Coil at Cryogenic Environment)

  • 이민래;권영길;이준현;손명환
    • 대한기계학회논문집A
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    • 제24권4호
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    • pp.858-865
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    • 2000
  • It is well recently recognized that quench is one of the serious problems for the integrity of superconducting magnets, which is mainly attribute to the rapid temperature rising in the magnet due to some extrinsic factors such as conductor motion, crack initiation etc. In order to apply acoustic emission(AE)echnique effectively to monitor and diagnose superconducting magnets, it is essential to identify the sources of acoustic emission. In this paper, an acoustic emission technique has been used to monitor and diagnose quenching phenomenon in racetrack shaped superconducting magnets at cryogenic environment of 4.2K. For these purposes special attention was paid to detect AE signals associated with the quench of superconducting magnets. The characteristics of AE parameters have been analyzed by correlating with quench number, winding tension of superconducting coil and charge rate by transport current. In addition, the source location of quench in superconducting magnet was also discussed on the basis of correlation between magnet voltage and AE energy.

분리된 삼상 자속구속형 전류제한기와 일체화된 삼상 자속구속형 전류제한기의 전류제한 특성 비교 (Comparison of Fault Current Limiting Characteristics between the separated Three-phase Flux-lock Type SFCL and the Integrated Three-phase Flux-lock Type SFCL)

  • 두승규;두호익;김민주;박충렬;김용진;이동혁;한병성
    • 한국전기전자재료학회논문지
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    • 제22권8호
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    • pp.689-693
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    • 2009
  • We investigate the comparison of fault current characteristics between the separates three-phase flux-lock type superconducting fault current limiter(SFCL) and integrated three-phase flux-lock type superconducting fault current limiter(SFCL). The single-phase flux-lock type SFCL consists of two coils. The primary coil is wound in parallel to the secondary coil on an iron core and superconducting elements are connected to secondary coil in series. Superconducting elements are used by the YBCO coated conductor. The separated three-phase flux-lock type SFCL consists of single-phase flux-phase type SFCL in each phase. But the integrated three-phase flux-lock type SFCL consists of three-phase flux-reactors wound on an iron core. Flux-reactor consists of the same turn's ratio between coil 1 and coil 2 for each single phase. To compare the current limiting characteristics of the separated three-phase flux-lock type SFCL and integrated three-phase flux-lock type SFCL, the short circuit experiments are carried out fault condition such as the single line-to-ground fault. The experimental result shows that fault current limiting characteristic of the separated three-phase flux-lock type SFCL was better than integrated three-phase flux-lock type SFCL. And the integrated three-phase flux-lock type SFCL has an effect on sound phase.

$2{\times}3$구조의 매트릭스형 초전도 한류기의 트리거 코일 및 션트 저항에 따른 특성 (Characteristics of Matrix Type SFCL with $2{\times}3$ Array According to the Trigger Coil and Shunt Resistance)

  • 정병익;최효상
    • 전기학회논문지P
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    • 제58권1호
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    • pp.85-89
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    • 2009
  • We investigated the quench characteristics in accordance with increase of turns number of trigger coil and shunt resistance of matrix-type superconducting fault current limiter (SFCL) with $2{\times}3$ array. The matrix-type SFCL consists of the trigger part to apply magnetic field and the current-limiting part to limit fault current. The fault current limiting characteristics according to the increase of magnetic field and applied voltage were nearly same. This is because the application of magnetic field hasn't an affect on total impedance of the SFCL. When turns number of a reactor increased, the voltage difference between two superconducting units in the current-limiting part according was decreased. The resistance difference generated in two superconducting units was also decreased. Therefore, we confirmed that the differences of the critical behaviors between superconducting units were reduced by application of magnetic field. By this results, we could decide the optimum turns number of reactor to apply magnetic field.

자속구속형과 저항형 초전도 전류제한기의 특성비교 (Comparison of Operating Characteristics between Flux-lock Type and Resistive Type Superconducting Fault Current Limiters)

  • 박형민;임성훈;박충렬;최효상;한병성
    • 한국전기전자재료학회논문지
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    • 제18권4호
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    • pp.363-369
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    • 2005
  • we compared the operating characteristics between flux-lock type and resistive type superconducting fault current limiters(SFCLs). Flux-lock type SFCL consists of two coils, which are wound in parallel each other through an iron core, and a high-Tc superconducting(HTSC) element is connected with coil 2 in series. The the flux-lock type SFCL can be divided into the subtractive polarity winding and the additive polarity winding operations according to the winding directions between the coil 1 and coil 2. It was confirmed from experiments that flux-lock type SFCL could improve both the quench characteristics and the transport capacity compared to the resistive type SFCL, which means, the independent operation of HTSC element.

변류기(p-CT)를 적용한 YBCO 초전도 저항형 한류기의 ?치 특성 (Quench Behaviors of Superconducting YBCO film for Fault Current Limiters applying Protective Current Transformer)

  • 박권배;이방욱;강종성;오일성;현옥배
    • Progress in Superconductivity
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    • 제5권2호
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    • pp.128-131
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    • 2004
  • The resistive superconducting fault current limiters (SFCLs) are very attractive devices for the electric power network. But they have some serious problems when the YBCO thin films were used for the current limiting materials due to the in homogeneities caused by manufacturing process. When the YBCO films have some inhomogeneities, simultaneous quenches are difficult to achieve when the fault current limiting units are connected in series for increasing operating voltage ratings. Magnetic field application is one of the prospective way of inducing simultaneous quenches far the series-connected resistive FCL components. Magnetic field was typically generated by the fault current thorough a coil, which is connected to components of the fault current limiter in series, leaving the problem, which provides significant inductance to the power line and suppresses critical current density of the superconducting components. In this article we investigated the possible application of the protective current transformer (p-CT), which is available current source to the magnetic coil. This system inductively coupled to the circuit, therefore, remarkably reducing impedance to the circuit. The current by the protective current transformer was directly fed to the coil, generating magnetic field large enough to reduce critical current density of the components. This successfully induced simultaneous quenches of the series-connected resistive FCL components.

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Computation of the Current Limiting Behavior of BSCCO-2212 High-Temperature Superconducting Tube with Shunt Coils

  • Kim, H.M.;Park, K.B.;Lee, B.W.;Oh, I.;Sim, J.;Hyun, O.B.
    • 한국초전도ㆍ저온공학회논문지
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    • 제8권4호
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    • pp.22-25
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    • 2006
  • This paper deals with the computation of the current limiting behavior of high-temperature superconducting (HTS) modules for the superconducting fault current limiter (SFCL). The SFCL module consists of a monofilar type BSCCO-2212 tube and a shunt coil made of copper or brass. The shunt coil is connected to the monofilar superconducting tube in parallel. Through analysis of the quench behavior of the monofilar component with shunt coils, it is achieved to drive an equivalent circuit equation from the experimental circuit structure. In order to analyze the quench behavior of the SFCL module, we derived a partial differential equation technique. Inductance of the monofilar component and the impedance of the shunt coil are calculated by Bio-Savart and Ohm's formula, respectively. We computed the quench behavior using the calculated values, and compared the results with experimental results for the quench characteristics of a component. The results of computation and test agreed well each other, and it was concluded that the analytic result could be applied effectively to design of the distribution-level SFCL system.