Experimental Results of High-Efficiency Resonant Coupling Wireless Power Transfer Using a Variable Coupling Method

• Published in: IEEE microwave and wireless components letters Vol. 21; no. 8; pp. 442 - 444
• Main Authors: Duong, Thuc Phi, Lee, Jong-Wook
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.08.2011; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Circuit properties; Circuits; Coils; Coupling coefficient; Couplings; efficiency; Electric, optical and optoelectronic circuits; Electronic circuits; Electronics; Equivalent circuits; Exact sciences and technology; Frequency measurement; Integrated circuit modeling; Joining; magnetic resonance; Matching; Mathematical models; Microwaves; Oscillators, resonators, synthetizers; Power transfer; Power transmission; Resonant frequency; Resonators; Wireless communication; wireless power transfer; Performance evaluation; Resonator; efficiency; Coupling coefficient; Resonant coupling; Magnetic resonance; Equivalent circuit; Coupling factor; Wireless electricity; wireless power transfer
• ISSN: 1531-1309; 1558-1764
• DOI: 10.1109/LMWC.2011.2160163

We experimentally demonstrate that the efficiency of wireless power transfer utilizing resonant coupling is improved by applying the "matching condition." The `matching condition' is extracted from an equivalent circuit model of a magnetically coupled wireless power transfer system. This condition is achieved by varying the coupling factor between the source (load) and the internal resonator. Applying this technique results in efficiency improvements of 46.2% and 29.3% at distances of 60 cm and 1 m, respectively. The maximum efficiency is 92.5% at 15 cm. A circuit model based on the extracted parameters of the resonators produces results similar to the experimental data.