Finite element modeling of eddy currents in a multiconductor system with quasi-2D symmetry

Purpose The purpose of this paper is to introduce a fast and resource-efficient method for modeling litz wires with complex structures. The method is also capable of taking into account nonlinear materials in the configuration (e.g. ferrite-core coil). Design/methodology/approach The modeling of litz wires is performed in two-dimensional (2D), with the key being the proper consideration of three dimension (3D) phenomena (twisting, constraints resulting from braiding, winding and the circuit constraints) in 2D. These phenomena can be taken into account through specific constraint conditions, which, when incorporated into the boundary value problem equations, enable the system of equations to be solved in a single step. Findings With the developed method, 3D problems related to wire modeling can be solved in 2D by eliminating superposition. As a result, the model can handle nonlinearities such as a magnitude-dependent complex permeability, allowing for the modeling of ferrite-core coils as well. A comparison between a simple 2D-3D model example demonstrates significant time savings, while the 2D model reproduces the results of the 3D model fairly well. The 2D model can also be extended to wires with more complex structures, the modeling of which in 3D would require extremely high computational power, if feasible at all. Originality/value This paper shows the applicability of the 2D model as a substitute for the 3D model by showing the agreement of the results, as well as the savings in computation time and performance.