Current transport and FCL properties of polycrystalline melt textured YBCO

Toward demonstrating the potential of resistive HTS fault current limiting behavior bulk polycrystalline melt textured (pmt) YBCO devices in meander-like shape were developed and tested by using 50 Hz AC pulses at 77 K. Meander fabrication is based on high-dense and temperature gradient growth textured YBCO plates, which were mechanically stabilized, diamond tooling CAD cut and prepared with low resistive Cu contacts in lengths between 1-5 m. The nonideal I-V characteristics at normal operation due to the residual grain boundary resistivity was measured to a few tens of microvolts per centimeter at 1000 A. Due to additional metallic shunt layer the conditions for quench protection of inherently inhomogeneous material have been derived, tested and substantially improved. We investigated the feasibility, technical performance and economy of employing robust pmt YBCO to take decisions about the material line of future superconducting fault current limiter (FCL) modules.