Cabling Method of HTS Flat Tape Superconducting Wires

Applications

Superconducting wires are used for power transmission cables, magnet conductors, data server centers, power distribution in microgrids, and power transmissions from alternative energy sources.

Problem Addressed

Existing superconducting wires can increase their capacity with a parallel arrangement of the wires. However, there is a significant amount of heat loss caused by resistive and magnetic hysterisis generated by flux couplings in the loop circuits among the superconducting wires. By twisting the superconducting wires, the magnetic flux coupling is heavily reduced. There exists a demand for high current capacities in both AC and DC applications that current technologies are not capable of sustaining. Therefore, the high current capacities of the High Temperature Superconductors (HTS) needed for practical applications can be acquired with the removal of accompanying AC losses or magnetic flux coupling losses.

Technology

The basic cable has a plurality of flat, tape-shaped ribbon superconductor wires assembled to form a stack having a rectangular cross section. The stack has a twist about the longitudinal axis of the stack. The wires are ReBCO (YBCO, GdBCO), BSCCO, or MgB2 tape conductors. The basic cables can be twisted together to form a larger cable that transmits higher electric current. The twisting is important in order to reduce undesired magnetic flux coupling between superconducting wires as well as to increase mechanical bendability . The superconducting cable is disposed within and spaced apart from an electrical insulator, and the space between the cable and the insulator provides a channel for coolant. A cryostat surrounds the insulator to create a return coolant channel for thermal insulation. 

Advantages

  • Adaptability in both AC and DC applications over wide ranges of current and voltage
  • Significantly higher current density of power cables and magnet conductors, even for very high magnetic fields
  • Increases mechanical strength of  the superconductor
  • Obtains better thermal cooling