Wireless Power Transfer using EF2 Inverter with Fixed Coil Capacitor and Air core Inductor

This work proposes a wireless power transfer system using EF2 inverter at the transmitter side, that implements magnetic resonance coupling. The receiver side is tested both for AC and DC load. The ferrite cores of EF2 inverter are replaced by air core inductors to reduce the weight and to avoid the core saturation limit. The issue of variable capacitance by varying the distance between transmitter and receiver coil is addressed by using fixed capacitance. A 40W scaled down laboratory prototype is developed to validate the proposed idea. Power is transferred wirelessly up to a distance of 70 mm at a switching frequency of 1 MHz with an efficiency of 85%. Fast switching device, GaN MOSFET is used to reduce the ON state loss as well as high frequency switching losses.