• 제목/요약/키워드: Quench Detection System

검색결과 6건 처리시간 0.022초

Numerical estimation on balance coefficients of central difference averaging method for quench detection of the KSTAR PF coils

  • Kim, Jinsub;An, Seok Chan;Ko, Tae Kuk;Chu, Yong
    • 한국초전도ㆍ저온공학회논문지
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    • 제18권3호
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    • pp.25-29
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    • 2016
  • A quench detection system of KSTAR Poloidal Field (PF) coils is inevitable for stable operation because normal zone generates overheating during quench occurrence. Recently, new voltage quench detection method, combination of Central Difference Averaging (CDA) and Mutual Inductance Compensation (MIK) for compensating mutual inductive voltage more effectively than conventional voltage detection method, has been suggested and studied. For better performance of mutual induction cancellation by adjacent coils of CDA+MIK method for KSTAR coil system, balance coefficients of CDA must be estimated and adjusted preferentially. In this paper, the balance coefficients of CDA for KSTAR PF coils were numerically estimated. The estimated result was adopted and tested by using simulation. The CDA method adopting balance coefficients effectively eliminated mutual inductive voltage, and also it is expected to improve performance of CDA+MIK method for quench detection of KSTAR PF coils.

Study on quench detection of the KSTAR CS coil with CDA+MIK compensation of inductive voltages

  • An, Seok Chan;Kim, Jinsub;Ko, Tae Kuk;Chu, Yong
    • 한국초전도ㆍ저온공학회논문지
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    • 제18권1호
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    • pp.55-58
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    • 2016
  • Quench Detection System (QDS) is essential to guarantee the stable operation of the Korea Superconducting Tokamak Advanced Research (KSTAR) Poloidal Field (PF) magnet system because the stored energy in the magnet system is very large. For the fast response, voltage-based QDS has been used. Co-wound voltage sensors and balanced bridge circuits were applied to eliminate the inductive voltages generated during the plasma operation. However, as the inductive voltages are hundreds times higher than the quench detection voltage during the pulse-current operation, Central Difference Averaging (CDA) and MIK, where I and K stand for mutual coupling indexes of different circuits, which is an active cancellation of mutually generated voltages have been suggested and studied. In this paper, the CDA and MIK technique were applied to the KSTAR magnet for PF magnet quench detection. The calculated inductive voltages from the MIK and measured voltages from the CDA circuits were compared to eliminate the inductive voltages at result signals.

펄스전류 운전에 따른 KSTAR PF 초전도자석의 퀜치 분석 및 퀜치 검출 시스템 운전 특성 (Quench Analysis and Operational Characteristics of the Quench Detection System for the KSTAR PF Superconducting Coils)

  • 추용;요네가와;김영옥;이현정;박갑래;오영국
    • 한국초전도ㆍ저온공학회논문지
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    • 제11권3호
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    • pp.20-25
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    • 2009
  • The quench detection system of the KSTAR (Korea Superconducting Tokamak Advanced Research) primarily uses the resistive voltage measurement due to a quench. This method is to detect the resistive voltage generated by a quench, which is continuously maintained above the preset voltage threshold for a given holding time. As the KSTAR PF (Poloidal Field) coils are operated in the pulse current mode, the large inductive voltages are generated. Therefore the voltage threshold and the quench holding time should be determined by considering both the inductive voltages measured during the operation, and the maximum conductor temperature rise through the quench analysis. In this paper, the compensation methods for minimizing the inductive voltages are presented for the KSTAR PF coils. The quench hot spot analysis of the PF coils was carried out by the analytical and numerical methods for determining the proper values of the quench voltage threshold and the allowable quench protection delay time.

초전도 Power Supply의 전류펌핑 과정에서 발생하는 조기 퀜치발생 진단 (A study on the Detection of Premature Quench Generated in the Process of Current Pumping in a Superconducting Power Supply)

  • 김호민;배준한;노정섭;심기덕;장원갑;고태국
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 하계학술대회 논문집 A
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    • pp.244-246
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    • 1997
  • This paper is to analyze the Premature Quench characteristics of a rotating magnet type superconducting fluxpump and consider the method of detecting and protecting this premature quench. Practically, there is contact resistance between the fluxpump and the load, namely the S.C. magnet. The thermal increase due to the contact resistance cause the premature quench before the charging current amounts to the critical current of S.C magnet. Therefore, this paper is devoted to solving the heat equation on contact region using cylindrical coordinates and to calculating the rate of thermal increase during the current is pumped up. Doing so, the predictive value of the maximum pumping current is obtained. It has been verified that the results of simulation are coincident with those of experiment. It must be considered essentially to minimize the contact resistance in designing the S.C fluxpump system in order to protect the premature quench and improve the maximum pumping current.

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초전도자석내의 국부적 상변이에 대한 열적.전기역학적 해석 및 퀜치보호시스템의 설계 및 특성해석 (The Analysis of Quench Protection System through Thermo-Electrodynamics of Resistive Transition in SC Magnet)

  • 추용;배준한;김호민;장미혜;주민석;고태국;김기만;정상권
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 하계학술대회 논문집 A
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    • pp.86-88
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    • 1997
  • The detection of the normal zones in the coil winding and the initiation of the proper dump sequence have been one of the most important areas in the superconducting magnet technology. In this paper, the process to derive optimal dump sequence has been investigated through quench simulation and analysis of magnetically coupled superconducting magnet system. The magnet terminal voltage and maximum temperature rise in the quench initiated point are calculated with respect to various input variables such as operation current, dump resistance, etc. The experimental system is comprised of sc solenoidal coil, data aquisition device, external circuit breakers and dump resistor. The quench behavior of the magnet(e.g., temperature profile and the voltage signal) was measured. From this results, theoretical predictions were found to coincide with the experimental observations.

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단락 사고 검출용 고온초전도체의 초전도성 회복 시간 변화 측정 (Recovery time after quench of Au/YBCO thin film for fault accident detection)

  • 임성우;김혜림;현옥배;성태현;심정욱
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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    • pp.246-247
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    • 2007
  • 최근 KEPRI-LSIS가 공동 개발한 하이브리드형 초전도 한류기 동작 시, 사고 검출을 담당하는 초전도체의 최적 설계에 적용하기 위하여 Au/YBCO 박막의 ��치 회복 특성을 조사하였다. $600\;V_{rms}$, 3 ms의 사고가 초전도 박막에 인가되었을 때, ��치가 종료된 이후 초전도성을 회복하기 위해 142 ms의 시간이 소요되었다. 또한 인가 시간이 증가함에 따라 소요 시간도 비례하여 증가하여 4 ms 동안 인가되었을 때, ��치 회복 시간은 272 ms로 측정되었다.

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