Coupling-Independent Capacitive Wireless Power Transfer with One Transmitter and Two Receivers Using Frequency Bifurcation

Capacitive wireless power transfer utilizes capacitive coupling to transfer electrical energy wirelessly. However, with variation in distance or alignment, this coupling varies and as a result the efficiency and power transfer varies. In this work, we propose a frequency agile mode, using frequency bifurcation, that allows for a nearly coupling-independent regime for a capacitive wireless power transfer system with one transmitter and two receivers. The conditions for bifurcation are described and analytical expressions for the power and transducer gains are determined. It is shown that, when operating at the secondary resonances, nearly constant efficiency and power transfer to the load can be achieved.