Sumitomo has been working on motor application for its superconducting wire for a number of years. In 2008, SEI unveiled an electric vehicle equipped with a prototype superconducting motor cooled by liquid nitrogen and built using SEI’s high-temperature superconducting (HTS) wires. The Sumitomo motor developed around 30kW with 120 N·m torque.
In September, 2007, a Japanese research group coordinated by IHI Corporation and including SEI unveiled a 365 kW HTS motor cooled by liquid nitrogen and using SEI’s DI-BSCCO superconducting wire. SEI’s bismuth-based superconducting material is made of bismuth - strontium - calcium - copper - oxygen (Bi-Sr-Ca-Cu-O).
Superconductors have zero resistance to the flow of electricity, so a vehicle with such a motor could consume 20-30% less energy than a conventional electric car using copper wire, according to the company.
The Nikkei reported that SEI hopes to start mass-producing the motors by 2020 and envisions applications in not only buses, but also forklifts and small trucks.