Date of Award


Document Type

Open Access Dissertation


Computer Science and Engineering

First Advisor

Enrico Santi


Wireless power transfer (WPT) technology provides galvanic isolation for improved safety and also provides reliability by eliminating the need for dedicated connectors/adapters that can get damaged due to frequent usage. For these reasons, it has become popular in medical implant charging and electric vehicle (EV) charging. Beyond these niche applications, due to aesthetic features and convenience provided by the cord-free environment, it is rapidly becoming an attractive charging solution for various portable electronics as well as household appliances. However, currently available WPT technology demonstrates several shortcomings and various challenges due to allowed receiver position variation with respect to transmitter position. For consumers, major shortcomings and challenges include lower power transmission efficiency compared to hard-connected charging method and limited receiver positioning flexibility. For the industry, major shortcomings and challenges include increased cost of implementation and increased complexity in design and control.

In order to promote adoption of WPT technology, it is important to provide good power transmission efficiency and to improve receiver positioning flexibility while reducing complexity in design and control of resonant converters. Also, it is important to minimize the component count to reduce the cost of implementation.

In this research, novel optimal design methods have been developed for resonant converters employing two popular resonant tank topologies: series-series (SS) resonant tank and series-parallel (SP) resonant tank. Also, a novel control method for SS resonant converter employing a symmetrical inductive coupler has been developed. These methods reduce complexity in analysis, design, and control. Using these methods, receiver positioning flexibility can be improved without a large component count while minimizing design complexity. Various simulation results and experimental results are presented to show that these methods allow achieving an optimal compromise between power transmission efficiency and power delivery robustness against variations in resonant tank parameters occurring due to magnetic coupling variation.


© 2013, Isaac Nam