Numerical modelling and AC losses of multifilamentary Bi-2223/Ag conductors with various geometry and filament arrangement

This paper presents results from numerical modelling of non-twisted multifilamentary Bi-2223/Ag conductors with various geometry and filament arrangement. New anisotropic models of Jc(B) and n(B) have been employed in finite element method simulations under different operating conditions – with applied AC transport current, in external parallel and perpendicular AC magnetic field, and with combined current and field of varying orientation. AC losses, as well as current and magnetic flux densities in square and round Bi-2223/Ag wires with different filament arrangement have been calculated and compared to those of a 7-filamentary tape. The notion of effective Ic(B) in transport current applications is introduced and discussed. It is demonstrated that the shape factor of the conductors and the orientation of the local magnetic field with respect to the individual filaments are of primary importance for the AC loss magnitude in different applications. Outlined are the advantages of using conductors with specific filament configuration for a given application.