Inductively-coupled wireless power transfer
(WPT) system is broadly adopted for charging batteries
of mobile devices and electric vehicles. The performance
of the WPT system is sensitively dependent on the
strength of electromagnetic coupling between the coils,
compensating topologies, loads and airgap variation.
This paper aims to present a comprehensive characteristic
analysis for the design of the WPT system with a
numerical simulation tool. The electromagnetic field
solver FEKO is mainly used for studying high-frequency
devices. However, the computational tool is also
applicable for not only the analysis of the electromagnetic
characteristic but also the identification of the electrical
parameters in the WPT system operating in the nearfield. In this paper, the self and mutual inductance of the
wireless transfer windings over the various airgaps were
inferred from the simulated S-parameter. Then, the
formation of the magnetic coupling and the distribution
of the magnetic fields between the coils in the seriesparallel model were examined through the near-field
analysis for recognizing the efficient performance of the
WPT system. Lastly, it was clarified that the FEKO
simulation results showed good agreement with the
practical measurements. When the input voltage of 10 V
was supplied into the transmitting unit of the prototype,
the power of 5.31 W is delivered with the transferring
efficiency of 97.79% in FEKO. The actual measurements
indicated 95.68% transferring efficiency. The electrical
parameters; in , out, in , , in , and out, had a fair
agreement with the FEKO results, and they are under
8.4% of error