Recursive Domain Decomposition Approach in 2-D Time-Harmonic Wireless Power Transfer Simulations Considering Litz Wires

A recursive domain decomposition approach based on 2-D time-harmonic finite element (FE) model with AVI formulation is used to model a wireless power transfer (WPT) unit with litz wires. Similar techniques exist in the literature but they haven’t yet been applied to WPT units. The approach produces a model which is significantly faster to update and re-solve than a traditional FE model and hence it is suitable for performing parametric sweeps where the positioning of the coils is varied. Using the technique it is possible to study losses emerging in individual strands even with extremely high number of strands. The loss distribution between the litz wire strands is studied, varying the number of strands from 7 to 925. The results and speed are compared to a traditional FE AVI model. The method yields results up to a 1 % relative error compared to the traditional model with a significantly faster simulation time.