Hybrid superconducting fault current limiter based on bulk melt textured YBa2Cu3O7 ceramic composites

A hybrid fault current limiter (FCL) based on single domain bars of Y123/211 melt textured composites has been designed to operate at a 1 kV/400 A line. This consists of a conventional Cu primary coil inductively coupled to a secondary coil formed by the paralleling of single Cu turns each one shorted by a superconducting bar. The superconducting material has been prepared by the solidification techniques of Bridgman and Top Seeding in air which has allowed us to obtain bars with transport critical current densities of 20000 A/cm(2) at 77 K. Preliminary tests on the quench current, recovery time and aclosses in normal operation have been performed. The differences and advantages of a hybrid FCL in comparison with a resistive and an inductive FCL will be discussed.