Speaker
Prof.
Naoyuki Amemiya
(Kyoto University)
Description
Numerical electromagnetic field analyses are powerful tools to study the ac loss characteristics of superconductors. If they are combined with thermal analyses, they are also useful to study the quench characteristics of superconductors. Here, we focus on (RE)BCO coated conductors. Electromagnetic field analyses in the cross-section of a coated conductor have been made widely to study its ac loss characteristics, and the focus of interest are shifting to the assemblies of coated conductors such as cables or coils. However, cables or coils are generally with three-dimensional geometries, and their analyses are much more complicated than those of single coated conductors. A peculiarity of coated conductors from the viewpoint of numerical analyses is its extremely thin superconductor layer: its cross-sectional aspect ratio is 2000~10000. This leads to a difficulty in numerical modelings. If we keep a moderate cross-sectional aspect ratio for each element, a large number of elements must be generated in just one cross-section of the superconductor layer; the number of elements in an entire three-dimensional model should be too large for practical calculation. One of the approaches against this problem is a thin strip approximation where the magnetic field component tangential to the superconductor layer and the current density normal to it are neglected. Models for electromagnetic field analyses of superconducting Roebel cables as well as power transmission cables have been developed based on this approximation. The results of analyses by using the models to calculate ac losses are also presented.
This work was supported in part by Japan Science and Technology Agency under Strategic Promotion of Innovative Research and Development Program.
Author
Prof.
Naoyuki Amemiya
(Kyoto University)
Co-authors
Mr
Masahiro Nii
(Kyoto University)
Dr
Taketsune Nakamura
(Kyoto University)
