Live Coupling Coefficient Calculation Method for Capacitive Wireless Power Transfer with Multiple Receivers

Capacitive wireless power transfer shows promise for wireless energy delivery, utilizing capacitive coupling for transmission. Quantifying the coupling between individual transmitters and receivers is essential, as optimization techniques for optimal output impedance depend on accurate knowledge of the coupling coefficient. Methods to measure this coupling exist, but these are applied to a specific configuration of a capacitive power transfer system, requiring a new measurement each time the distance or alignment between transmitters and receivers change. Since practical capacitive power transfer systems often experience variations in distance or alignment, impacting the coupling coefficient and consequently, the optimal output impedance, it is desired to constantly measure the coupling coefficient. This paper proposes a concise, exact method for live coupling coefficient calculation, and looks into the application of this method for systems with one transmitter and one receiver, and one transmitter and multiple receivers.