TY - JOUR
T1 - Transient stability analysis taking into account hall effect for large aluminum stabilized superconductor
AU - Kawawada, Nobuki
AU - Noguchi, So
AU - Igarashi, Hajime
AU - Ishiyama, Atsushi
AU - Yanagi, Nagato
AU - Imagawa, Shinsaku
N1 - Funding Information:
Manuscript received September 20, 2005. This work is partially supported by the cooperative research program in NIFS (code KOBA015). N. Kawawada, S. Noguchi, and H. Igarashi are with the Graduate School of Information Science and Technology, Hokkaido UniversityHokkaido 060-0814, Japan (e-mail: noguchi@ssi.ist.hokudai.ac.jp). A. Ishiyama is with the Department of EECE, Waseda University, Tokyo 169-8555, Japan. N. Yanagi and S. Imagawa are with the National Institute for Fusion Sciences,Gifu 509-5292, Japan. Digital Object Identifier 10.1109/TASC.2006.871309
PY - 2006/6
Y1 - 2006/6
N2 - Aluminum stabilized superconductors are used in accelerators, SMES, and fusion devices, such as the LHD helical coils. These superconductors have large-cross sectional area of high purity aluminum to improve their stability. However, one of the important properties of these superconductors is the transient stability, which is caused by a long duration of transport current transfer from the superconducting strands into the aluminum in a normal-state region. Once a normal zone is initiated in such superconductors, excess joule heat is generated in a small region of the aluminum stabilizer near the superconducting strands during the transport current diffusion time. It hence deteriorates the transient stability. Therefore, it is important to investigate the characteristics of the transient stability by numerical analysis. The latest experiments of the LHD helical coil conductor show an asymmetrical propagation of normal zone along the longitudinal direction of the conductor. The Hall current generation is clearly one of the causes of this phenomenon. The Hall current generation prevents the transport current from transferring between the superconducting strands and the aluminum stabilizer. It causes the asymmetrical transport current distribution, and affects the stability of the superconductor. In order to simulate the normal-zone propagation in the superconductor more preciously and to clarify the cause of the asymmetrical propagation, we have developed a 2D finite element analysis code taking account of the Hall effect and investigated the transient stability of large aluminum stabilized superconductors.
AB - Aluminum stabilized superconductors are used in accelerators, SMES, and fusion devices, such as the LHD helical coils. These superconductors have large-cross sectional area of high purity aluminum to improve their stability. However, one of the important properties of these superconductors is the transient stability, which is caused by a long duration of transport current transfer from the superconducting strands into the aluminum in a normal-state region. Once a normal zone is initiated in such superconductors, excess joule heat is generated in a small region of the aluminum stabilizer near the superconducting strands during the transport current diffusion time. It hence deteriorates the transient stability. Therefore, it is important to investigate the characteristics of the transient stability by numerical analysis. The latest experiments of the LHD helical coil conductor show an asymmetrical propagation of normal zone along the longitudinal direction of the conductor. The Hall current generation is clearly one of the causes of this phenomenon. The Hall current generation prevents the transport current from transferring between the superconducting strands and the aluminum stabilizer. It causes the asymmetrical transport current distribution, and affects the stability of the superconductor. In order to simulate the normal-zone propagation in the superconductor more preciously and to clarify the cause of the asymmetrical propagation, we have developed a 2D finite element analysis code taking account of the Hall effect and investigated the transient stability of large aluminum stabilized superconductors.
KW - Aluminum stabilized superconductor
KW - Hall effect
KW - Normal-zone propagation velocity
KW - Transient stability
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U2 - 10.1109/TASC.2006.871309
DO - 10.1109/TASC.2006.871309
M3 - Article
AN - SCOPUS:33746622963
SN - 1051-8223
VL - 16
SP - 1717
EP - 1720
JO - IEEE Transactions on Applied Superconductivity
JF - IEEE Transactions on Applied Superconductivity
IS - 2
M1 - 1643192
ER -