A New Asymmetrical Half-Bridge Converter With Zero DC-Offset Current in Transformer

This paper proposes an asymmetrical half-bridge (AHB) converter with a new secondary rectifier. Due to the new rectifier stage, the proposed AHB converter has a zero dc-offset current in the transformer at any operating conditions so that the transformer core loss becomes very small compared to the conventional AHB converter. This results in higher efficiency. Besides, magnetic components can be optimally utilized because maximum flux density can be applied when designing the magnetic components. It also allows a flexible design to improve the efficiency or reduce the cost. This paper presents the operation principle and relevant analysis results of the proposed converter. A 300 W, 200-400-V input, and 50-V output laboratory prototype operating at 100 kHz is built and tested to verify the effectiveness of the proposed converter.