Power Synthesis Network for Megahertz Inverter System in Wide Load Operation Range

A novel power synthesis network and active modulation strategy for a megahertz inverter system in a wide load impedance range are proposed in this paper. The wide load impedance range is converted into equivalent pure-resistive branch load impedances of two inverters by modulating the inverter input voltage ratio and output phase difference. In view of the wide pure-resistive load range, the load-independent resonant inverters are adopted for constant ac current source output and soft switching. Moreover, the constant ac output can be achieved by modulating the input voltages of two branches. To validate the proposed method, an experimental prototype operating at 13.56 MHz with an ac current output of 2.0 A was constructed, achieving a peak efficiency of 89.35%.