High efficient multi-level half-bridge converter

A new high efficient multi-level half-bridge converter is proposed in this paper. The proposed converter regulate the output voltage by adjusting additional voltage on a main transformer with an auxiliary circuit while main switches are operated at fixed duty ratio and switching frequency. Therefore, no magnetizing dc offset current is existed in the main transformer and all switches can realize zero voltage switching (ZVS). Furthermore, a multi-level voltage shown at the output filter reduces the output inductance significantly. To verify these features of the proposed circuit, operational principles, and experimental results will be presented with a 700 W prototype.