Design of high current superconducting DC power cable using the longitudinal magnetic field configuration

It was shown that the current-carrying capacity of a superconducting DC power cable could be dramatically increased using the longitudinal magnetic field effect. That is, the force-free structure was assumed for the conductor in the cable to use a significant enhancement of the critical current density in a parallel magnetic field observed in metallic superconductors. However, the critical current density of present commercial coated conductors decreases slightly with increasing the longitudinal magnetic field. Hence, the fundamental design of the cable must be changed to obtain a higher current-carrying capacity. In spite of a poor critical current density in the longitudinal magnetic field, it is still appreciably higher than that in a transverse magnetic field. A new design is introduced for a superconducting DC power cable suitable for present coated conductors. It is shown that the current-carrying capacity can be remarkably increased from conventional cables.