PREPARATION OF HIGH T-C SUPERCONDUCTING COILS FOR CONSIDERATION OF THEIR USE IN A PROTOTYPE FAULT CURRENT LIMITER

High Te superconducting coils, made using Ag clad (Bi,Pb)SrCaCuO-2223 wires, have been used for building a small prototype of an electrical transmission system fault current limiter. The techniques for fabricating high T-c superconducting coils with the Bi-2223 Ag clad long wire are described, which include transferring the long wire to coils and wire-joining techniques to enhance total current ampere-turns of such coils. The testing with these coils includes the magnetic field dependence of its critical current I-c the mechanical bending property and cracks on the superconductor. The prototype based on the principle of a magnetic core saturable reactor is studied. The results from the superconducting coils and the prototype are helpful for evaluating the application of the high T-c superconductors in the electrical system.