Comparison of optimal configuration of SMES magnet wound with MgB ₂ and YBCO conductors

This paper describes a comparison of an optimal configuration of SMES magnets wound with MgB₂ or YBCO conductors. For YBCO SMES, it is well known that a toroidal magnet is an ideal structure from the view point of the influence of the perpendicular component of magnetic field applied to an YBCO tape. We investigated an ideal structure for MgB₂ SMES by comparing with the YBCO SMES. Because an MgB₂ wire has no anisotropic magnetic property like an YBCO tape, the toroidal structure is unsuitable for MgB ₂ SMES. Therefore, we proposed a new structure of MgB₂ SMES where the magnetic flux leaking between conductors is avoided. An MgB ₂ SMES of the proposed structure can store approximately 5.6 times higher than that of a single solenoid structure with the same winding volume.