Optimization Procedure of Complex Permeability for a Wireless Power Transfer System


Wireless power transfer (WPT) is fundamentally based on Faraday's law of induction and uses relatively strong magnetic field to transfer the required power from the source to the load without any electrical contact. To reduce the leakage magnetic field and enhance the magnetic coupling between the coils, soft magnetic material such as ferrite is frequently used. However, it is hard to determine the optimum magnetic properties to meet the various design requirements such as the cost, the efficiency and the regulations for the time-varying electromagnetic field (EMF) exposure. In this paper, we present the procedure to find the optimum complex permeability satisfying the following design requirements: the transfer efficiency of 90% and the minimum levels of EMF around the coils. The results show that solely maximizing the real part of complex permeability or minimizing the magnetic loss tangent is unsuitable to meet the given design requirements for the WPT system.

Meeting Name

Asia-Pacific Symposium on Electromagnetic Compatibility, APEMC 2013 (2013: May 20-23, Melbourne, Australia)


Electrical and Computer Engineering

Keywords and Phrases

Complex Permeability; Electromagnetic Field; Ferrite; Magnetic Material; Wireless Power Transfer

International Standard Book Number (ISBN)


Document Type

Article - Conference proceedings

Document Version


File Type





© 2013 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

23 May 2013