Loss Performance Evaluation of Ferrite-Cored Wireless Power System with Conductive and Magnetic Shields

Abstract

This paper presents a loss evaluation of ferrite-cored wireless power transfer (WPT) systems using conductive and magnetic shield materials. The modelling and analyses of the coil systems were implemented using the finite element method. Three coil systems were modelled-circular coils, rectangular coils and flux-pipe coil system using magnetic shields (Mumetal and electrical steel) and conductive shields (aluminium and copper). From the results presented in the analyses, it was noted that ohmic losses and core losses in the WPT system are independent of the type of conductive shield used. Similarly, it was noted that the self-inductance, coupling coefficient and losses in the system is affected by the type of magnetic shield used. For the flux-pipe resonant coil system, high amount of power losses was recorded when a magnetic shield was used as the shielding topology while low amount of power losses was recorded in the circular coil and rectangular coil resonant systems when the magnetic shield was used as the shielding material. For an optimal WPT system requiring a low amount of eddy current losses, it was established that copper shield is the appropriate choice for flux-pipe resonant coils while electrical steel is the suitable shield material for the circular resonant coil and rectangular resonant coil systems.

Performance Analysis of Different Shielding Material for A 100W Wireless Power Transfer System

“…The coupling coil design consideration is the most important due to its significant factors in the WPT system. To improve the efficiency of the coupling coil some studies have suggested to add magnetic shielding as a core material as shown in [3]- [6].…”

Performance analysis of wireless power transfer using series-to-series topology

“…The primary issue with WPT is power losses, therefore the convenience of not using wires comes at a price. While conduction loss in a conventional copper cable connection is not negligible, losses in WPT are significantly more [15], [16]. A large amount of alternating current is required to generate a magnetic field strong enough to link two separated coils.…”