AC loss and stability analysis in multifilamentary superconductors based on temporal evolution of current/temperature distribution

The temporal evolution of current and temperature distribution in multifilamentary superconductors was calculated numerically, while they are carrying the transport current and are exposed to spatially-distributed magnetic field. Thermo-magnetic instabilities in superconductors operating at commercial frequency are initiated when their AC loss becomes maximum. When the external magnetic field is distributed axially, the radial current profile is also distributed axially. This leads to additional coupling loss. In steady state, the temperature rise due to losses is negligible. Quench process has been simulated dynamically, with the external magnetic field distributed axially. During the quench process, large temperature gradient along the conductor axis appears. The magnetic and thermal diffusions along the axis improve the stability limit against thermo-magnetic instabilities