A self-tuning 100 watt wireless power transfer system

Abstract

This thesis presents a new method of controlling wireless power transfer suitable for highly resonant magnetically coupled systems. An application of this system is unattended autonomous operation such as recharging of autonomous underwater vehicles or underwater sensor networks. Special attention is given to maximizing power transfer even when there may be spatial variations in transfer distance, which shifts the resonance peak frequency and hence requires automated control. An automated system comprised of a 100 watt switching power amplifier coupled to a frequency controller is designed and implemented. The desired operating frequency is determined by quantification of the real-time AC power supplied to the resonant transmitter. The control system is preset to select operation at either of two selectable modes inherent to the resonant structure. The implemented system can operate underwater, requires only DC voltage inputs and operates over a range of distances while self-tuning to peak power transfer.