Design Optimization of Round Strands Made by Twisted Stacks of HTS Tapes

A twisted stack of high-temperature superconducting (HTS) tapes soldered into copper profiles was used as a strand in the fabrication of the 60-kA/12-T HTS cable prototype at the Center for Research in Plasma Physics (CRPP). Considering the strand in general as a modular element for the high-current cables, design parameters of the strand need to be optimized in order to best fulfill requirements of appropriate application field. During the development program of the HTS fusion cable at CRPP, influence of the design parameters on the strand's performance was obtained as input data for the optimization process. In this paper, we summarize the results of the twisting, bending, and transverse pressure tests on strands of various tapes and profile's geometries. Finite-element model for the transverse pressure test was developed, validated with the test results, and used for the design proposals. Effect of the stack aspect ratio, tape properties, and anisotropy, as well as selection of HTS material for the strand, will be discussed.

[1]  Christian Barth,et al.  Electro-mechanical properties of REBCO coated conductors from various industrial manufacturers at 77 K, self-field and 4.2 K, 19 T , 2015, 1502.06713.

[2]  Klaus-Peter Weiss,et al.  Influence of Shear Stress on Current Carrying Capabilities of High Temperature Superconductor Tapes , 2011, IEEE Transactions on Applied Superconductivity.

[3]  Liping Liu.  THEORY OF ELASTICITY , 2012 .

[4]  Joseph V. Minervini,et al.  HTS twisted stacked-tape cable conductor , 2011 .

[5]  Nikolay Bykovskiy,et al.  HTS high current cable for fusion application , 2017 .

[6]  R. Wesche,et al.  Strain Management in HTS High Current Cables , 2015, IEEE Transactions on Applied Superconductivity.

[7]  C. Basaran,et al.  Measuring intrinsic elastic modulus of Pb/Sn solder alloys , 2002 .

[8]  W Goldacker,et al.  Finite Element Analysis of Torsion Experiments on HTSC Tapes , 2011, IEEE Transactions on Applied Superconductivity.

[9]  Wilfried Goldacker,et al.  Status of high transport current ROEBEL assembled coated conductor cables , 2009 .

[10]  A. H. Cooke,et al.  Materials at Low Temperatures , 1963, Nature.

[11]  Arend Nijhuis,et al.  Experiments and FE modeling of stress–strain state in ReBCO tape under tensile, torsional and transverse load , 2015 .

[12]  Makoto Takayasu,et al.  Temperature-and field dependent characterization of a twisted stacked-tape cable , 2015, 1502.06728.

[13]  R. Wesche,et al.  Fabrication Trials of Round Strands Composed of Coated Conductor Tapes , 2013, IEEE Transactions on Applied Superconductivity.

[14]  Amalia Ballarino,et al.  Electro-mechanical properties of PIT Nb3Sn wires under transverse stress: experimental results and FEM analysis , 2015 .

[15]  Loren F. Goodrich,et al.  Compact GdBa2Cu3O7–δ coated conductor cables for electric power transmission and magnet applications , 2011 .