An investigation on frequency characteristics of wireless power transfer systems with relay resonators
ISSN: 0332-1649
Article publication date: 6 November 2017
Abstract
Purpose
This paper aims to analyze the frequency characteristics of wireless power transfer (WPT) systems with relay resonators in terms of the power delivered to the load and system efficiency. Based on the analytical results, system parameters can be optimized to achieve maximum power transfer and higher system efficiency.
Design/methodology/approach
Based on Kirchhoff’s voltage law equations, WPT systems with relay resonators are described by the coupled linear second-order differential equations. Splitting frequencies are estimated by using the matrix theory. In addition, critical coupling conditions are demonstrated based on discriminant analysis.
Findings
It was found that multi-maximum values exist for the power delivered to the load and total system efficiency owing to multiple eigenfrequencies of the system. Also, frequency conditions of maximum power transfer and system efficiency, as well as their critical coupling conditions, were quantitatively estimated.
Research limitations/implications
During our analytical process, we assume that quality factors of resonators in the system are high and the crossing coupling between resonators is negligible.
Originality/value
In previous works, the exact analysis of frequency characteristics is limited to WPT systems with two resonators. The appealing feature of this work lies in its ability to present a simplified analytical method with negligible approximation errors for WPT systems with relay resonators.
Keywords
Acknowledgements
This work was supported by the Key Program of the National Natural Science Foundation of China under Grant 51437005 and the National Natural Science Foundation of China under Grant 51677074.
Citation
Zhou, J., Zhang, B. and Qiu, D. (2017), "An investigation on frequency characteristics of wireless power transfer systems with relay resonators", COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, Vol. 36 No. 6, pp. 1594-1611. https://doi.org/10.1108/COMPEL-12-2016-0538
Publisher
:Emerald Publishing Limited
Copyright © 2017, Emerald Publishing Limited