Numerical modeling of MgB₂ conductors for high power AC transmission

Highlights: • We explore the potential of MgB₂ cables for high power AC transmission. • We discuss the main aspects relevant for designing a cable with low AC losses. • The cable is modeled by FEM to the scale of individual filaments. • The AC loss is comparable to that of HTS cables of similar current capacity. • Magnetization losses dominate: there is big potential for cable optimization. - Abstract: Cables made of MgB₂ superconductors are currently explored as a viable solution for transporting high electrical power in the AC regime. In order to be competitive against the DC solution, the cables need to have an acceptable level of AC losses. In this contribution, we discuss the main aspects relevant for designing a cable with a sufficiently low AC loss level. To this end, we perform finite-element-method (FEM) simulations to determine the current and field distributions and calculate the AC losses of such cable configuration. For current capacities of 2–5 kA (peak), power cables are assembled from a relatively small number of MgB₂ strands. The performance of such cables strongly depends on the current and field distributions, which are in turn influenced by the number and the arrangement of the superconducting components and also by the magnetic properties of supporting materials. Numerical simulations can help to test different cable configurations and provide important insights for optimizing the cable’s design. The numerical model includes the field dependence of the superconductor’s critical current density J_c(B) as well as the non-linear properties of magnetic materials