Patent ID: 7724482

Claim:
A superconducting transformer system configured to be included within a utility power grid having a known fault current level, the superconducting transformer system comprising: a non-superconducting transformer interconnected between a first node and a second node of the utility power grid; and a superconducting transformer interconnected between the first node and the second node of the utility power grid, the superconducting transformer and the non-superconducting transformer being electrically connected in parallel, and the superconducting transformer having a lower series impedance than the non-superconducting transformer when the superconducting transformer is operated below a critical current level and a critical temperature, the superconducting transformer including one or more HTS wires, wherein at least one of the one or more HTS wires includes one or more stabilizer layers having a total thickness within a range of 200-500 microns and a resistivity within a range of approximately 0.8-15.0 microOhm-cm at approximately 90K; wherein the superconducting transformer is configured to have a series impedance that is at least N times the series impedance of the non-superconducting transformer when the superconducting transformer is operated at or above one or more of the critical current level and the critical temperature, wherein N is greater than 1 and is selected to attenuate, in conjunction with an impedance of the non-superconducting transformer, the known fault current level by at least 10%.