Earticle

초록

영어

AC Losses for face to face stacks of four identical coated conductors (CCs) were numerically calculated using the H-formulation combined with the E-J power law and the Kim model. The motive sample was the face to face stack of four 2 mm-wide CC tapes with 2 μm thick superconducting layer of which the critical current density, Jc, was 2.16×106 A/cm2 on IBAD-MgO template, which was suggested for the mitigation of ac loss as a round shaped wire by Korea Electrotechnology Research Institute. For the calculation the cross section of the stack was simply modeled as vertically aligned 4 rectangles of superconducting (SC) layers with E = Eo(J(x,y,t)/Jc(B))n in x-y plane where Eo was 10-6 V/cm, Jc(B) was the field dependence of current density and n was 21. The field dependence of the critical current of the sample measured in four-probe method was employed for Jc(B) in the equation. The model was implemented in the finite element method program by commercial software. The ac loss properties for the stacks were compared with those of single 4 cm-wide SC layers with the same critical current density or the same critical current. The constraint for the simulation was imposed in two different ways that the total current of the stack obtained by integrating J(x,y,t) over the cross sections was the same as that of the applied transport current: one is that one fourth of the external current was enforced to flow through each SC. In this case, the ac loss values for the stacks were lower than those of single wide SC layer. This mitigation of the loss is attributed to the reduction of the normal component of the magnetic field near the SC layers due to the strong expulsion of the magnetic field by the enforced transport current. On the contrary, for the other case of no such enforcement, the ac loss values were greater than those of single 4cm-wide SC layer and . In this case, the phase difference of the current flowing through the inner and the outer SC layers of the stack was observed as the transport current was increased, which was a cause of the abrupt increase of ac loss for higher transport current.

목차

Abstract
 1. INTRODUCTION
 2. NUMERICAL SIMULATION
  2.1. Sample Modeling
  2.2. Superconducting Modeling
  2.3. Boundary Conditions and Constraints
 3. RESULTS AND DISCUSSION
 4. CONCLUSION
 ACKNOWLEDGMENT
 REFERENCES

키워드

저자

• Jaeun Yoo [ Department of Physics, Chonbuk National University, Jeonju, Korea ] Corresponding author
• Dojun Youm [ Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon, Korea ]
• SangSoo Oh [ Superconducting Materials Research Group, KERI, Changwon, Korea ) ]

참고문헌

발행기관

간행물

표지보기 관심저널 등록

• 간행물명

  한국초전도·저온논문지 (구 한국초전도저온공학회논문지) [Progress in Superconductivity and Cryogenics]

• 간기

  계간

• pISSN

  1229-3008

• eISSN

  2287-6251

• 수록기간

  1999~2026

• 등재여부

  KCI 등재,SCOPUS

• 십진분류

  KDC 427 DDC 537