In the push to develop high power motors and generators, fully superconducting technology promises to significantly reduce mass and volume. However, challenges related to AC Loss and thermal management are a significant factor in preventing the proliferation of fully superconducting motors and generators. Increasing the resistance of the metal matrix stabilization has only gone so far in reducing coupling currents for higher frequency applications. In this research, Multiphysics simulations of a single composite filament were used to investigate stability decreases when using very high thermal conductivity electrical insulator (CsI) or metal-to-insulator transitioning material (V₂O₃) to replace the slightly resistive metal matrix typically used for a low AC loss MgB₂ composite wire. The insulators separate the MgB₂ filaments entirely, only allowing transient current sharing to occur with the high purity Nb diffusion barrier or with the metallic state V₂O₃. These simulations show that for these very low AC loss composites at 20 K, instability will become a major issue due to reductions in current sharing. Higher electrical conductivity metal-to-insulator materials, higher thermal conductivity impregnation materials, and thicker metallic diffusion barriers are investigated to find a reasonable balance between AC-loss and stability.

Keywords: AC Loss, MgB2, Superconductor, Motor