Development of 2 MVA Class Superconducting Fault Current Limiting Transformer (SFCLT) with YBCO Coated Conductors

Abstract

We have been developing a Superconducting Fault Current Limiting Transformer (SFCLT) with the functions of both superconducting transformer in normal operating condition and superconducting fault current limiter in fault condition. As the Step-5 of our SFCLT project, in this paper, we designed and fabricated a 2 MVA class HTS-SFCLT using YBCO coated conductors with the ratings of 3-phase and 22 kV/6.6 kV. The developed HTS-SFCLT is characterized by a hybrid structure of HTS coils using YBCO, YBCO/Cu and Bi2223 tapes for design flexibility as both the superconducting transformer and the superconducting fault current limiter. Fundamental tests of the HTS-SFCLT were carried out, and its design parameters as a superconducting transformer were verified.