DocumentCode :
110703
Title :
An Adaptive Impedance-Matching Network Based on a Novel Capacitor Matrix for Wireless Power Transfer
Author :
Yongseok Lim ; Hoyoung Tang ; Seungok Lim ; Jongsun Park
Author_Institution :
Sch. of Electr. Eng., Korea Univ., Seoul, South Korea
Volume :
29
Issue :
8
fYear :
2014
fDate :
Aug. 2014
Firstpage :
4403
Lastpage :
4413
Abstract :
In a wireless power transfer (WPT) system via the magnetic resonant coupling, one of the most challenging design issues is to maintain a reasonable level of power transfer efficiency (PTE), even when the distance between the transmitter and the receiver changes. When the distance varies, the PTE drastically decreases due to the impedance mismatch between the resonator of the transmitter and that of the receiver. This paper presents a novel serial/parallel capacitor matrix in the transmitter, where the impedance can be automatically reconfigured to track the optimum impedance-matching point in the case of varying distances. The dynamic WPT matching system is enabled by changing the combination of serial and parallel capacitors in the capacitor matrix. An interesting observation in the proposed capacitor matrix is that the resonant frequency is not shifted, even with capacitor-matrix tuning. In order to quickly find the best capacitor combination that achieves maximum power transfer, a window-prediction-based search algorithm is also presented in this paper. The proposed resonance WPT system is implemented using a resonant frequency of 13.56 MHz, and the experimental results with 1W power transfer show that the transfer efficiency increases up to 88 % when the distance changes from 0 to 1.2 m.
Keywords :
capacitors; impedance matching; matrix algebra; radiofrequency power transmission; search problems; PTE; adaptive impedance-matching network; capacitor-matrix tuning; dynamic WPT matching system; frequency 13.56 MHz; magnetic resonant coupling; optimum impedance-matching point; power 1 W; power transfer efficiency; receiver changes; resonant frequency; resonator; serial-parallel capacitor matrix; transmitter; window-prediction-based search algorithm; wireless power transfer system; Capacitance; Capacitors; Coils; Impedance; Receivers; Resonant frequency; Transmitters; Capacitor matrix; impedance matching; impedance searching; magnetic resonant coupling; wireless power transfer (WPT);
fLanguage :
English
Journal_Title :
Power Electronics, IEEE Transactions on
Publisher :
ieee
ISSN :
0885-8993
Type :
jour
DOI :
10.1109/TPEL.2013.2292596
Filename :
6675068
Link To Document :
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