Modelling stacked conductors
Simulated is a stack of two superconducting tapes, carrying AC currents dephased by 180 degrees, supplied by two independent current sources.
Superconductor properties of each tape: Jc=3.9*109 A/m2, n=30, Ic=1170 A
Losses in each tape: P = 0.32 W/m (with Ip=600A, f=59 Hz)
Losses are thus reduced by a factor of 2 compared to one insulated tape (P = 0.57 W/m), carrying the same current (Ip=600A).
Current distribution (in A/m2), Ip=600A, wt=p/2 (peak value)
In this case the zones with high current density are pushed towards the edge of the tape, closer to the other tape, which is due to the magnetic attraction between the two tapes. In an isolated tape the current density distribution would comprise of a current-free zone in the center and full current density zone in the periphery of the tape.
Magnetic field distribution (in T), wt=p/2.
Due to the opposite current flowing in the two tapes, the magnetic field is superposed in-between and almost canceled near the edges, see next picture.
Magnetic field direction, wt=p/2 (grey=air, yellow=silver, red=SC)
Work by Svetlomir Stavrev & Francesco Grilli