Three-coil wireless power transfer system using class E2 resonant DC-DC converter

This paper presents the analysis and design of an inductively-coupled wireless power transfer system implemented using a three-coil arrangement and the Class E² resonant DC-DC converter. The three-coil structure is modeled using FastHenry simulation software. The theory of reflected impedance is used to determine the optimum operating conditions. A practical application having an output voltage of 15 V, output power of 10 W, and operating at 5 MHz is considered to support the analysis. Simulation results are provided for the given specifications. For the given coil geometry and fixed component values, an efficiency of 88.5% was achieved for a separation of 1.5 cm between the transmitter and receiver.