TY - JOUR
T1 - Measurements of current distributions in a multi-laminated HTS tape conductor for solenoid coils
AU - Hamajima, Takataro
AU - Jifang, He
AU - Harada, Naoyuki
AU - Tsuda, Makoto
AU - Yazawa, Takashi
AU - Kuriyama, Toru
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2004/5
Y1 - 2004/5
N2 - A multi-laminated HTS tape conductor has recently been developed for large coils. If the HTS tapes are simply laminated to form the conductor, the current distribution in the laminated tape conductor of the coil is unbalanced because of the differences among all tape inductances. Transposition of the tape in the conductor is effective for homogeneous current distribution, but the tape may be damaged due to the lateral bending. In our previous paper, we proposed a new theory to analyze and control current distributions in the multi-laminated tape conductor for a solenoid coil with arbitrary layers. We applied the Maxwell integral equation to the region contoured by adjacent laminated tapes to analyze the current distributions of the tapes in the infinite solenoid coil, demonstrated that the flux across the region is conserved as long as the tapes are not saturated, and finally induced fundamental equations as functions of coil construction parameters, such as layer radius, laminated tape space, and winding pitch. In order to verify the theory, we designed two kinds of coils with homogeneous and inhomogeneous current distributions in the two-laminated tape conductor by adjusting the space between the tapes in the second layer, and fabricated them. In the case when the space between the tapes in the second layer is the same as that of the first layer, 0.31 mm in thickness, we measured the tape currents of 7:3 for the inner and outer tape of the first layer, respectively. We adjusted the space between the tapes of the second layer, 1.78 mm in thickness, while the space of the first layer remained unchanged, 0.31 mm in thickness. We obtained the homogeneous current distribution in the tape conductor. The experimental data were in good agreement with the theory.
AB - A multi-laminated HTS tape conductor has recently been developed for large coils. If the HTS tapes are simply laminated to form the conductor, the current distribution in the laminated tape conductor of the coil is unbalanced because of the differences among all tape inductances. Transposition of the tape in the conductor is effective for homogeneous current distribution, but the tape may be damaged due to the lateral bending. In our previous paper, we proposed a new theory to analyze and control current distributions in the multi-laminated tape conductor for a solenoid coil with arbitrary layers. We applied the Maxwell integral equation to the region contoured by adjacent laminated tapes to analyze the current distributions of the tapes in the infinite solenoid coil, demonstrated that the flux across the region is conserved as long as the tapes are not saturated, and finally induced fundamental equations as functions of coil construction parameters, such as layer radius, laminated tape space, and winding pitch. In order to verify the theory, we designed two kinds of coils with homogeneous and inhomogeneous current distributions in the two-laminated tape conductor by adjusting the space between the tapes in the second layer, and fabricated them. In the case when the space between the tapes in the second layer is the same as that of the first layer, 0.31 mm in thickness, we measured the tape currents of 7:3 for the inner and outer tape of the first layer, respectively. We adjusted the space between the tapes of the second layer, 1.78 mm in thickness, while the space of the first layer remained unchanged, 0.31 mm in thickness. We obtained the homogeneous current distribution in the tape conductor. The experimental data were in good agreement with the theory.
KW - Homogeneous current distributions
KW - Laminated tape conductor
KW - Maxwell integration equation
KW - Solenoid coil
KW - Transposition
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U2 - 10.1016/j.cryogenics.2004.02.002
DO - 10.1016/j.cryogenics.2004.02.002
M3 - Article
AN - SCOPUS:2042537331
VL - 44
SP - 349
EP - 355
JO - Cryogenics
JF - Cryogenics
SN - 0011-2275
IS - 5
ER -