Design of Loosely Coupled Magnetic Systems Based on Finite Element Method for Inductive Power Transfer Applications

Abstract

This paper proposes an iterative approach for the design of loosely coupled inductors for inductive power transfer applications. The procedure is based on the finite element method and is suitable for realistic coil geometry development where non-linear magnetic materials are required. Dedicated algorithms represent self-inductances and mutual inductances in terms of equivalent geometric parameters and vice-versa thus allowing an approach that is not possible in analytical formulations. Also, finite element method is used to analyze the coil system, with two or more coils, under axial, lateral and angular misalignment prior to the development of prototypes. The iterative method can be used to support development of wireless power converters for biomedical implants, electric vehicles recharging systems and chargers for portable devices, with simple and minor modifications. Also, it has specific tools for geometry optimization that can lead to maximized power transfer. Experimental results are presented for coupling coefficient under spatial misalignment.