Design performance of a superconducting power link

Superconducting power links (SUPERPOLI) will offer a low-loss power transmi ssion and fault current limitation in a single del ice. In the European SUP ERPOLI project, a long term goal is to build a 200 nr long, 20 kV(rms), 28 kA(rms) 3-phase superconducting power link which will be refrigerated by su bcooled liquid nitrogen, The SUPERPOLI will have a compact coaxial multitub e structure which significantly reduces the ac losses, As a step towards th is GVA-class application, a 2 m long, 28 kV, 2 kA/5 kA, one-phase functiona l model is under construction. The conductor variants considered are Bi-221 2 bulk conductor and Y-123 coated film conductor, They present very differe nt behaviors in normal operation and during the limiting phase: Bi-2212 bul k conductor has higher ac losses and allows short transients or moderate ov er-currents without quenching, while Y-123 film has low ac losses and immed iate response for overcritical currents.