Study on Cost Reduction of SMES System, Using Nb₃Sn Conductor

Abstract

A cost-reduction design of the SMES system is proposed, using Nb₃Sn conductors that in recent years have shown progress in cost and performance. The main feature of this design should be a combination of Nb₃Sn single-strand conductors and a small bore solenoid (=CELL) coil. The cost reduction was intended to use mass production methods and to operate small or medium-sized factories. However, this simple and compact design brings up new issues. Quench protection is especially a key issue. It needs high-speed quench detection and forced-quench that will reduce the unbalance magnetic force at quench and prevent the CELL coil from burning up. This cost-reduction design of the SMES system using Nb₃Sn conductors is sufficiently competitive with the other designs that use NbTi conductors.