SUPERCONDUCTING LINEAR SYNCHRONOUS MOTOR FOR URBAN TRANSPORT-SYSTEM

It is presented the basic project of a superconducting linear synchron ous motor (SLSM) for high capacity urban transport system (10(6) passe ngers/day/line) able to go up hill grade of 12%. The motor is composed of 26 poles installed below one wagon and sufficient for traction of six wagons of 330 passengers each. The pole coil is a segmented race-t rack type 23 cm long, 140 cm wide, and 11.2 cm high. The conductor is composed of 14 transposed NbTi wires phi 0.7 mm each, 5.04 mm x 1.20 m m cross-section and Cu/SC ratio of 1.35. The current leads are made of high-T-c superconductor (melt textured growth YBa2Cu3O7-x). These lea ds allow a pool cooling cryostat (2400 l of LHe) without an on-board r efrigerator, and with one year holding time. The quench protection is made with cross-quench heater resistance placed within each coil. The limiting factor is the critical field of the NbTi and its substitution by Nb3Sn should reduce the cost by a factor of 40%. Final cost of the SLSM is expected to be in the US$ 600,000 range. Due to the low speed (100 km/h), the suspension is made on conventional bus type tyres.