Equivalent Parameters of Round and Litz Wire Conductors to Obtain an Equivalent Layer to Accelerate Finite Element Simulations of Wireless Power Transfer System

In Wireless Power Transfer system, the optimization of the electromagnetic coupling is one of the main problems. Since the geometry usually is 3D, closed analytical equations cannot be obtained. Due to the small dimensions of the winding's diameters and the high number of conductors compared to the large size of the coupler, the brute force simulations by Finite Element analysis is not feasible. In this work, a new method to overcome this limitation is proposed that is based on the use of an equivalent layer that behaves as the actual winding. Finite Element Simulations are accelerated by the use of an equivalent conductor with homogeneous current distribution. Skin and proximity losses are accounted by the modification of the conductivity and the complex permeability of the new equivalent conductor meanwhile the field energy is accounted by the real permeability. The new electromagnetic parameters are obtained by means of analytical equations.