Since April 1997 the running tests of the superconducting maglev system have been carried out at Yamanashi maglev test line, which is located about 100 km west from the center of Tokyo, aiming at its practical application. Construction of a commercial line has already started between Tokyo and Nagoya. The distance is about 290 km and the commercial service is plan to start in 2027. The extension of the line to Osaka is also planned and its commercial service will start in 2045 or earlier. The commercial line between Tokyo and Osaka is called “Chuo Shinkansen,” which will be the Tokaido Shinkansen Bypass connecting three major metropolitan areas in Japan.
The superconducting maglev vehicles have superconducting magnets for the electrodynamic suspension and linear synchronous motor propulsion, and these technologies enable a super high-speed operation at 500 km/h with a lower noise and a higher efficiency. The magnets use NbTi superconducting wires cooled with liquid helium and 4 K GM-JT cryocoolers for the closed-loop cooling system. The superconducting racetrack coils are about 1.0 m long and 0.5 m high. Its magnetomotive force is 700 - 750 kA. A 16-car maglev train will have 34 superconducting magnets and 136 superconducting coils in total.
It has been approved that NbTi superconducting magnets have sufficiently good performance for revenue service. However, high-temperature superconducting magnets using Bi2223 or REBCO wires are highly expected to be introduced. They would have better stability and simpler cryostat structure, and need simpler cooling systems
