Generating performance of limiting impedance in flat type of fault current limiter with high Tc superconducting plate

We have proposed a flat type of the superconducting fault current limiter (FCL) which is a modified version of a magnetic shielding type of the fault current limiter. The new FCL basically consists of a doughnut-like form high Tc superconductor (HTS) plate and spiral coil, each of which works as a secondary one-turn winding and a primary winding, respectively. The FCL modules can be easily built up to make a large scale FCL. This simple construction may enable us to reduce the manufacturing costs. We made two small modules of the flat type FCL with Bi2223 bulk plate and YBCO thin film plate and investigated the generation of the limiting impedance due to an excess current. Higher ratio of the limiting impedance to normal one was produced by the YBCO thin film plate than by the Bi2223 bulk plate.