Frequency-Modulated Inductive-Resonant WPT System with Improved Efficiency

Approaches to get higher efficiency of switching-frequency-modulated inductive-resonant wireless power transfer systems (WPT) are proposed in the paper. The approaches are verified by using simulations. The approaches are based on utilization of modified resonant tanks with electronically-switched capacitors or electronically tunable capacitors. The approaches can sufficiently improve efficiency, reduce RMS and peak values of currents and reduce output current ripples of frequency-modulated WPT systems for battery charging.