The fabrication and analysis of bulk YBCO for use in an inductive fault current limiter.

To improve commericial confidence in high temperature superconductivity it is imperative that superconductors are produced and tested for specific applications. Fault Current Limiters (FCL) have the potential of becoming one of the first major applications of high temperature superconductors. In this work melt processed YBCO rings were produced for use in al inductive FCL. The effects of dopants such as Ag, CeO2, Ba4CuPt2O9 (0412), and combinations of the three, are illustrated, when combined with a base mixture of YBa2Cu3O7-x (YBCO) with 25wt% excess Y2BaCuO5 (211). The FCL is used to determine the critical current density (J(c)), rate of reaction to fault currents, and recovery from fault currents, of the ring samples. Characterisation of the material by polarised light microscopy, AC susceptibility, and vibrating sample magnetrometry (VSM) is discussed. The results of the materials characterisation will be discussed in relation to die samples performance in the fault current limiter. Various characteristics of bulk YBCO rings in an inductive FCL are also discussed. The results illustrate the feasibility of using bulk YBCO in inductive FCLs.