Achievement of 6.78-MHz and 3-kW Single Inverter in Continuous Operation

This paper proposes a design flow and implementation method of a high-frequency and high-power inverter for wireless power transfer(WPT) systems. This design flow is revealed to achieve zero-voltage-switching (ZVS) operation and lower the thermal resistance for 3-kW continuous operation in 6.78 MHz. The printed circuit board(PCB) and a dead time design are theoretically described to achieve ZVS operation. In addition, the performance of a heat dissipation structure for a surface-mounted device(SMD) is evaluated by comparison of three types of heat dissipation structures to reduce the thermal resistance effectively. As a result, the continuous operation of the inverter is demonstrated with a 3.3 kW prototype at 6.78-MHz in experimental.