Development of the prospective power transmission model system integrated under superconducting environment-PROMISE

A "prospective power transmission model system integrated under superconducting environment", abbreviated to PROMISE, has been constructed to verify the technical possibility of superconducting power transmission for the next generation. PROMISE is composed of a superconducting transformer, a superconducting fault current limiter and superconducting power cable of length 5 m. These three superconducting apparatus are enclosed together in a long scale cryostat to be kept at the liquid helium temperature of 4.2 K. The major insulation is provided by liquid helium. PROMISE withstands an AC voltage of 6 kV for 2 minutes with quite low partial discharge. A voltage-current synthetic test has proved that PROMISE has a transmission capability of 6,000 V-1,000 kVA. The fault current limiter actually limits overcurrent and prevents the other apparatus from quenching. Quench current level coordination is actually realized in PROMISE.<>