A high-efficiency pv grid-tied micro-inverter with soft switching for dc/ac stage

This paper presents a new high-efficiency micro-inverter. The topology consists of a high-efficiency LLC resonant converter and a traditional full-bridge inverter employing a new soft switching technique. The inverter stage works with one leg operating in high frequency and the other leg in line frequency. Both switches in high frequency leg are able to achieve ZVS without adding any components by controlling the inductor current bidirectional in one switching period. Finally a 250W micro-inverter prototype was built to verify the theoretical analysis and a peak efficiency of 98.5% for inverter stage is achieved.