Fault current tests of a 5-m HTS cable

The first industrial demonstration of a three-phase, BTS power transmission cable at the Southwire manufacturing complex is in progress, One crucial i ssue during operation of the 30-m HTS cables is whether they can survive th e fault current (which can he over an order of magnitude higher than the op erating current) in the event of a short circuit fault and how HTS cables a nd the cryogenic system would respond, Simulated fault-current tests were p erformed at ORNL on a 5-m cable, This single-phase cable was constructed in the same way as the 30-m cables and is also rated for 1250 A at 7.3 kV ac line-to-ground voltage. Tests were performed with fault-current pulses of u p to 15 kA (for 0.5 s) with pulse lengths of up to 5 s (at 6.8 kA). Althoug h a large voltage drop was produced across the HFS cable during the fault-c urrent purse, no significant changes in the coolant temperature, pressure, or joint resistance were observed. The cable survived all 15 simulated faul t-current shots without any degradation in its V-I characteristics.