Experimental Investigation of Parallel Connected YBCO Coated Conductors for Resistive Fault Current Limiters

Rapid development of the critical current density, homogeneity and the manufacturing process of commercially available YBCO coated conductors (CC) opens up new fields for power applications. The feasibility of superconducting fault current limiters (SCFCL) at medium and high voltage levels or for high current applications would be unimaginable without the concept of modular assembling. This means that CCs have to be connected in series according to voltage condition and in parallel according to specific current requirements to form the specific modules. The limiting behavior and the AC-losses of such a module can be defined by purposeful selecting components with different physical properties. This work presents the experimental results of a module of parallel connected CC with equal and different physical properties like stabilization and critical current (I_c). The tests are performed under different over-currents from minor overloads to fault currents and demonstrate the limiting behavior of a single CC and of the bundled CC in liquid nitrogen bath under ambient pressure.