6.4 MVA resitive fault current limiter based on Bi-2212 superconductor

ABB has recently successfully developed and tested a single phase 6.4 MVA superconducting fault current limiter (SCFCL) demonstrator, which is based on a novel conductor design and innovative Bi-2212 ceramic fabrication technology. At present, it represents the highest rated power reported for HTS based SCFCL. The employed SCFCL component is a composite consisting of layers of bulk Bi-2212 ceramic, resistive metallic electrical bypass and fibre reinforced plastic (FRP). The Bi-2212 conductor is fabricated in sheets with an area of 30×40 cm 2 by using a modified partial melt process and is subsequently structured into long length meanders. The as-processed Bi-2212 is non-textured and exhibits a uniform j c in the range of 3000–5000 A/cm 2. The employment of a robust bypass facilitates a uniform quench in the SCFCL component during a fault event. Depending on the level of prospective fault current, a fault current is typically reduced to around 10 times nominal current in the first current peak and further to 2–5 times after 50 ms into the fault. Test and simulation results of the 6.4 MVA demonstrator, together with the application prospects of such Bi-2212 based SCFCL are presented and discussed.