High-Efficient Multilevel Half-Bridge Converter

A new high-efficient multilevel half-bridge converter is proposed in this paper. The proposed converter regulates the output voltage by adjusting applied voltage on the main transformer with an auxiliary circuit while main switches are operated at both fixed duty ratio and switching frequency. Therefore, no magnetizing dc offset current exists on the main transformer and all switches can be operated with zero voltage switching condition. Furthermore, multilevel voltage shown at the output filter reduces the output inductance significantly. To verify these features of the proposed circuit, operational principle and experimental results will be presented with the 700 W prototype.