• Title, Summary, Keyword: Simultaneous quench

Search Result 44, Processing Time 0.035 seconds

Quench Characteristics of Superconducting Elements using Reactors at Series and Parallel Connections (직·병렬연결시 리액터를 이용한 초전도 소자의 퀜치 특성)

  • Choi, Hyo-Sang;Lim, Sung-Hun;Cho, Yong-Sun;Nam, Gueng-Hyun;Lee, Na-young;Park, Hyoung-Min
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.18 no.9
    • /
    • pp.863-869
    • /
    • 2005
  • We investigated quench characteristics of superconducting elements connected in series and parallel each other. The serial and parallel connections of superconducting elements causes a difficulty in simultaneous quench due to slight difference between their critical current densities. In other to induce simultaneous quench, we fabricated four type circuits; serially connected circuit before parallel connection, the circuit connected in parallel before serial connection, serially connected circuit before parallel connection with reactors, the circuit connected in Parallel before serial connection with reactors. We confirmed that the simultaneous quenches occurred in serial and parallel connections of superconducting elements using reactors. In addition, the power burden of superconducting elements was smaller than those of serial and parallel connections of superconducting elements without reactors.

Improvement of Quench Properties of a Superconducting Fault Current Limiter Using YBCO Films by Serial and Parallel Combinations (직.병렬 조합에 의한 박막형 초전도 한류기의 퀜치특성 개선)

  • 최효상;김혜림;현옥배
    • The Transactions of the Korean Institute of Electrical Engineers B
    • /
    • v.52 no.7
    • /
    • pp.315-319
    • /
    • 2003
  • We improved quench properties of a superconducting fault current limiter (SFCL) based on YBCO thin films by their serial and parallel combinations. The SFCL consisted of 6 switching elements fabricated of 4 inch-diameter YBCO thin films. The quench currents of the switching elements were distributed between 33.9 A and 35.6 A. Simple serial connection resulted in imbalanced power dissipation between switching elements even at the quench current difference of 0.6 A. On the other hand, $2{\times}2$ and $3{\times}2$ stack combinations produced simultaneous quenches. The $3{\times}2$ stack combination showed better simultaneous quench behavior than the $2{\times}2$ stacks. This is suggested to be because the currents between switching elements in parallel connection of the $3{\times}2$ stacks were more effectively redistributed than the $2{\times}2$ stacks.

Quench Characteristics of YBCO Film for Current Limiting Using Magnetic Field

  • 박권배;최효상;김혜림;현옥배;황시돌
    • Progress in Superconductivity
    • /
    • v.3 no.2
    • /
    • pp.252-256
    • /
    • 2002
  • We studied YBCO films for current limiting of the resistive type which utilizes a transition from superconducting to normal state caused by exceeding critical current. The films were deposited on sapphire substrates and covered by gold top layer. The current limiting element consists of 2 mm wide YBCO stripes connected in series. A serious problem in using YBCO films for current limiting is inhomogeneities caused by imperfect manufacturing. Therefore simultaneous quench is a difficult problem when elements for current limiting are connected in series. So some researchers have recently proposed using magnetic field and heating for simultaneous quench. We have measured extended exec trim field-current density(E-J) characteristics for current limiting elements of YBCO films in applied magnetic field of 0 - 130 mT. And we have investigated quench characteristics in current limiting elements and between elements of YBCO films in applied magnetic field. The result of the experiments show that the presence of applied magnetic fields induces uniform quench distribution fur the stripes in element at $50V_{rms}$, otherwise non-uniform quenches were observed. And simultaneous quenches between elements were investigated at $150V_{rms}$. We suggest that suppressing the critical current by increased fields due to fault current effectively forced the stripes of higher $J_{c}$(0) to quench, resulting in equalizing quench times.s.s.s.

  • PDF

Effects of Shunt Reactors on Quench Performance of the Superconducting Fault Current limiter (션트리액터가 초전도 한류기의 퀜치에 미치는 효과)

  • Lee, Na-Young;Nam, Gueng-Hyun;Park, Hyoung-Min;Cho, Yong-Sun;Choi, Hyo-Sang;Hwang, Jong-Sun;Han, Byoung-Sung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • /
    • pp.296-297
    • /
    • 2005
  • We have investigated the quench performance of shunt reactors in the parallel connection of resistive type superconducting fault current limiter (SFCL) components based on YBCO films. To increase voltage rating, components are connected in series and to increase current level, they are connected in parallel. This method has cauesd the unbalanced quench between each components. To improve the problem, we have compared the quench properties between the current limiting components without and with shunt reactors connected in parallel. To improve the quench performance, across individual SFCL components connected the shunt reactor in parallel. The components with shunt reactors successfully produced simultaneous quench, resulting from the bypass of the fault current in the direction of the shunt reactor.

  • PDF

Simultaneous Quench Analysis of a Three-Phase 6.6 kV Resistive SFCL Based on YBCO Thin Films (YBCO 박막을 이용한 3상 6.6kV 항형 초전도 한류기의 동시Quench 분석)

  • Sim J;Kim H. R;Hyun O. B
    • Progress in Superconductivity
    • /
    • v.6 no.1
    • /
    • pp.46-51
    • /
    • 2004
  • We fabricated a resistive type superconducting fault current limiter (SFCL) of 3-phase $6.6 kV_{rms}$ / rating, based on YBCO thin films grown on sapphire substrates with a diameter off inch. Each element of the SFCL was designed to have the rated voltage of $600 V_{rms}$ $/35A_{rms}$. The elements produced a single phase with 8${\times}$6 components connected in series and parallel. In addition, a NiCr shunt resistor of 23 $\Omega$ was connected in parallel to each of them for simultaneous quenches between the elements. Prior to investigating the performance of the 3 phase SFCL, we examined the quench characteristics for 8 elements connected in series. For all elements, simultaneous quenches and equal voltage distribution within 10% deviation from the average were obtained. Based on these results, performance of the SFCL for single line-to-ground faults was investigated. The SFCL successfully limited the fault current of $10 kA_{ rms}$ below 816 $A_{peak}$ within 0.12 msec right after the fault occurred. During the quench process, average temperature of all components did not exceed 250 K, and the SFCL was totally safe during the whole operation.

  • PDF

Studies of Simultaneous Quench of Superconducting YBCO Flims for Fault Current Limiter Under the Influence of Magnetic Fields (자기장인가에 따른 YBCO 박막형 한류기의 동시?치 연구)

  • 박권배;이방욱;강종성;오일성;최효상;현옥배
    • Progress in Superconductivity and Cryogenics
    • /
    • v.4 no.1
    • /
    • pp.84-88
    • /
    • 2002
  • The resistive fault current limiter (SFCL) is a very attractive device for power networks. But it has a serious Problem in using YBCO films for fault current limiter is inhomogeneities caused by imperpect manufacturing. So simultaneous quenches are a difficult problem which elements for current limiting are connected in series for increasing voltage ratings. We investigated extended electric field-current characteristics for current limiting element of YBCO film when O-130mT magnetic field is applied. And quench characteristics were investigated in over all element and between elements of YBCO films. From the experiments, it was shown that applied magnetic fields using solenoid coil induced uniform quench distribution for over all stripes and simultaneous quench in all elements for current limiting of YBCO film was realized. We have achieved resistive fault current limiter of 1.2kV/20A rating using magnetic field.

Quench characteristics of YBCO thin films using magnetic field source for superconducting fault current limiters

  • Lee, B.W.;Park, K.B.;Kang, J.S.;Oh, I.S.
    • Progress in Superconductivity and Cryogenics
    • /
    • v.6 no.2
    • /
    • pp.11-14
    • /
    • 2004
  • YBCO thin films have good characteristics for current limiting materials due to compact size and high current carrying capability. But the irregularities and the extreme thin thickness of YBCO films cause some difficulties in simultaneous quench and thermal shock protection. In order to solve these problems, vertical magnetic field generated from solenoid coil was applied to the YBCO element. And also to minimize the inductance caused by the serial connection of magnetic field source with superconducting elements, magnetic field source was separated from the power lines adapting protective current transformer. In this study, electric field-current (E-I) and quench characteristics of YBCO films were analyzed both by electrical measuring method and observations of bubble propagation. From the experiment results, it was revealed that the magnetic fields generated by surrounding coil could induce the uniform quench distribution for all stripes of current limiting units and finally simultaneous quenches were realized in all serial connection of YBCO elements. In addition, the separation of magnetic field source form electrical network could be good solution for simultaneous quench of YBCO films without any unnecessary effect caused by serial connection.

Simultaneous quenching phenomena of resistive superconducting fault current limiter connected in series (직렬연결된 저항형 한류기의 동시퀜치 현상)

  • 최효상;김혜림;임해용;김인선;현옥배
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
    • /
    • /
    • pp.91-94
    • /
    • 2000
  • We fabricated resistive super- conducting fault current limiters (SFCL) based on YBCO thin films grown on 2" diameter $Al_{2}O_{3}$ substrates. Two SFCLs with nearly identical properties. two SFCLs with nearly identical properties were connected in series to investigate simultaneous quenching. There was a difference of several half cycles in their quench starting time, although the difference was not more than 0.1 msec when they were operated separately. This imbalance was removed by connecting a shunt resistor to an SFCL in parallel. Increased power input at high voltages also reduced the initial imbalance in power dissipation. Further efforts on the simultaneous quench in SFCLs connected in series are on the way through methods such as the artificial control of quench speed.peed.

  • PDF

Quench properties of a resistive superconducting fault current limiter by current redistribution (전류재분배에 의한 저항형 초전도 한류기의 퀜치 특성)

  • Choi, Hyo-Sang;Kim, Hye-Rim;Cha, Sang-Do;Hyun, Ok-Bae;Hwang, Si-Dole
    • Proceedings of the KIEE Conference
    • /
    • /
    • pp.336-338
    • /
    • 2002
  • We improved quench properties of a superconducting fault current limiter (SFCL) based on YBCO thin films by their serial and parallel combinations. The SFCL consisted of 6 switching elements fabricated of 4 inch-diameter YBCO thin films. Simple serial connection resulted in imbalanced power dissipation between switching elements even at the quench current difference of 0.6A. On the other hand, $2{\times}2\;and\;3{\times}2$ stack combinations produced simultaneous quenches. The $3{\times}2$ stack combination showed better simultaneous quench behavior than the $2{\times}2$ stacks. This is suggested to be because the currents between switching elements in parallel connection of the $3{\times}2$ stacks were more effectively redistributed than the $2{\times}2$ stacks.

  • PDF