Simulations of Nonuniform Behaviors of Multiple No-Insulation (RE)Ba2Cu3O7-x HTS Pancake Coils During Charging and Discharging

This paper studies simulations of charging and discharging characteristics in a magnet system which has seven double pancake coils on the same axis and is made of (RE)Ba₂Cu₃O_7-x conductor using no-insulation winding approach. A numerical circuit network model is developed to take turn-to-turn contact resistivity into account and calculates the azimuthal and radial current components during charging and discharging. It is found that the current distribution is not uniform from the upper coil to the middle and from the coil inner diameter to the outer diameter. Moreover, current distribution tendency are opposite to each other in the charging and discharging processes. In addition, voltage and magnetic field are calculated and correlated to the current distribution analysis to understand uneven electromagnetic phenomena in the multiple-coil system.