Abstract: The fault current limiter in a cryogenic liquid heat transfer medium, employs a high temperature superconductor (HTS) element which has a high thermal resistance coating material encapsulating the high temperature superconductor to form an intermediate boundary layer between the HTS element and the heat transfer medium. The coating material has a thickness which enables it to minimize the retained heat in the HTS element during recovery from a fault condition, wherein substantially all heat transfer from the encapsulated high temperature superconductor element to the liquid cryogen heat transfer medium occurs at the nucleate boiling heat transfer rate.

Abstract: A method and apparatus for magnetically triggering a superconductor in a superconducting fault current limiter to transition from a superconducting state to a resistive state. The triggering is achieved by employing current-carrying trigger coil or foil on either or both the inner diameter and outer diameter of a superconductor. The current-carrying coil or foil generates a magnetic field with sufficient strength and the superconductor is disposed within essentially uniform magnetic field region. For superconductor in a tubular-configured form, an additional magnetic field can be generated by placing current-carrying wire or foil inside the tube and along the center axial line.