Improved design and system approach of a three phase inductive HTS fault current limiter for a 12 kVA synchronous generator

A further development of the high temperature superconducting (HTS) mini power plant (MPP) concept designed earlier by one of the authors is presented in the paper. HTS fault current limiters (FCL) will be inserted at the terminals of the synchronous generator. Joint operation of HTS generators (including fully superconducting generators) and HTS FCL's provide additional benefits viz. a significant increase of the generator's unit power rating as well as of its dynamic stability, shown in the paper. A three-phase inductive HTS FCL designed and built for the protection of a generator is made up of three one-phase units, each containing YBCO rings as secondary "windings." A new design idea was applied for the primary winding to further reduce the leakage reactance of the FCL resulting in low reactive power consumption. Simulations of the electromagnetic processes in the HTS FCL are shown. Theoretical studies on the joint operation of a fully superconducting generator and an HTS FCL are presented.