Critical Current and AC Ripple Loss Analysis of a Global Self-Shielding HTS DC Cable Made of Filament REBCO Tapes

For the high-temperature superconducting dc cable with the same current orientation in every layer, the maximum magnetic field generally arises in the outermost layer. When the cable transmits a large current, the generated strong magnetic field will make the utilization rate of tapes extraordinarily low. The current direction of two neighboring layers in the self-shielding sandwich cable is inverse, which can whittle the magnetic field interaction of each layer, so as to minish the critical current attenuation of REBCO tape. The previous global self-shielding dc cable adjusts the current distribution between layers to homogenize the magnetic field. However, this article proposes a new global self-shielding dc cable made of filament REBCO tapes, which adjusts the current distribution in each layer. The uniformity of magnetic field can be improved further by using filament tapes to wind the cable. In this article,
T-A
formulation is adopted to study the critical current and ac ripple loss of global self-shielding sandwich cables made of filament REBCO tapes in detail. The simulation results demonstrate that the structure made of filament tapes has better performance than the previous global self-shielding structure.