Design performance of a superconducting power link

Superconducting power links (SUPERPOLI) will offer low-loss power transmission and fault current limitation in a single device. In the European SUPERPOLI project, a long term goal is to build a 200 m long, 20 kV/sub rms/ 28 kA/sub rms/ 3-phase superconducting power link which will be refrigerated by subcooled liquid nitrogen. The SUPERPOLI will have a compact coaxial multitube structure which significantly reduces the AC losses. As a step towards this GVA-class application, a 2 m long, 20 kV, 2 kA/5 kA, one-phase functional model is under construction. The conductor variants considered are Bi-2212 bulk conductor and Y-123 coated film conductor. They present very different behaviors in normal operation and during the limiting phase: Bi-2212 bulk conductor has higher AC losses and allows short transients or moderate overcurrents without quenching, while Y-123 film has low AC losses and immediate response for overcritical currents.