Short Circuit Test of HTS Power Cable

The 500 m high temperature superconducting (HTS) cable developed by the Super-ACE (R&D of fundamental technologies for superconducting ac power equipment) project included copper layers as protection against short circuit current. The design policy was that liquid nitrogen would not vaporize when it was exposed to the short circuit current of 31.5 kA with 0.5 s. In order to establish the design policy, we have made nine 10 m samples with the same construction of the 500 m HTS cable and set three cables in the liquid nitrogen vessel. Both of balanced fault of three-line grounding (3LG) and unbalanced faults of one line grounding (1LG) and two-line grounding (2LG) have been set and fault currents have been applied to the HTS cables. After each fault, the critical current has been measured and we have confirmed no variation of I
_c
before and after each fault. HTS cables have not been damaged mechanically by the fault current of 31.5 kA with 0.5 s.