Regulated power transfer using self-tuned networks for capacitive wireless systems

In this paper, an adaptive multi-loop controller for capacitive wireless power transfer (WPT) systems is introduced. The new controller approach combines continuous frequency tracking and matching networks tuning on both the primary and secondary to regulate a target current to the receiving side at best power transfer conditions. This enables to effectively disengage the power delivery capabilities from the cross-coupling interactions between the transmitting and receiving sides, variations of the electrical circuits and capacitive medium. This paper highlights the complex functional relationships of the multi mixed-signal controller, and provides better insights on the dynamics and on the practical implementation of a closed-loop capacitive power transfer (CPT) system. An experimental self-tuned capacitive WPT prototype has been designed and implemented to verify closed-loop operation at the MHz range.