Finite element models for superconducting systems

Given the recent improvements of their physical properties, high-temperature superconductors are increasingly used in many applications ranging from particle accelerators and fusion magnets, to electrical machines and power cables. Accurate numerical models of their electric, magnetic, and thermal responses is therefore essential for the design of efficient systems. Specific issues are the strongly nonlinear electric response of superconductors and the consequences of their detailed constitutive laws on the macroscopic behavior. In this talk, recent developments in finite element models for type-II superconductors will be described in the context of the open-source toolkit Life-HTS. More specifically, the choice of a formulation to tackle the strongly nonlinear electric response of the superconducting materials will be discussed. Two study cases will be presented: a first one describing an helicoidally-wound tape, for which exploiting the symmetry allows the problem to be reduced to a 2D model with an effective anisotropic medium. The second study case illustrates a model of the macroscopic response of a system with a non-centrosymmetric pinning texture.