Abstract: In accordance with the present invention, modular corona shields are employed in a HTS device to reduce the electric field surrounding the HTS device. In a exemplary embodiment a fault current limiter module in the insulation region of a cryogenic cooling system has at least one fault current limiter set which employs a first corona shield disposed along the top portion of the fault current limiter set and is electrically coupled to the fault current limiter set. A second corona shield is disposed along the bottom portion of the fault current limiter set and is electrically coupled to the fault current limiter set. An insulation barrier is disposed within the insulation region along at least one side of the fault current limiter set. The first corona shield and the second corona shield act together to reduce the electric field surrounding the fault limiter set when voltage is applied to the fault limiter set.

Abstract: A current limiter having a plurality of current limiting units provided for electric paths constituting a plurality of phases. Each current limiting unit is constituted by a superconducting coil functioning as a first current limiting element formed in a non-inductive winding manner by connecting two superconducting coils in series, which superconducting coils are wound in opposite directions and equal in size and number of turns, and a superconducting coil functioning as a second current limiting element connected in parallel to the first current limiting element and having a predetermined impedance value. These current limiting units are contained within a cryostat and separated by a magnetic shield member for electromagnetically isolating the respective phases.