Transient stability analysis of large aluminum stabilized superconductor by 3D finite element method

Very large current composite superconductors are used in SMES coils and fusion applications. These superconductors have large cross-sectional areas of high purity aluminum to improve their stability and to enhance the overall current density. Once a normal zone is initiated in such superconductors, the current transfers from the superconducting strands to the aluminum stabilizer according to the temperature distribution. The time constant of current diffusion in the aluminum stabilizer, however, is very long due to the low electrical resistivity of aluminum. Therefore, excess joule heat is generated in a small region of aluminum stabilizer near superconducting strands and the temperature increases locally. Therefore, some 2D numerical analyses have been carried out in order to investigate the transient stability. However, recently, the performance of computer is enhanced and a huge numerical simulation becomes possible to be carried out. Therefore, we have developed a 3D finite element analysis codes and carried out some analyses. Finally, we compared the results of 2D and 3D analyses.