Design and Analysis of a High‐Efficiency Dual‐Module Asymmetrical Half‐Bridge Flyback Converter With Wide‐Output Voltage Range

ABSTRACT Asymmetrical half‐bridge (AHB) flyback converters achieve zero‐voltage switching (ZVS) on the primary‐side switches and zero‐current switching (ZCS) on the secondary‐side rectifier, resulting in high conversion efficiency and widespread use in the power supply industry. Furthermore, they use simple duty cycle control to regulate the output voltage, similar to isolated buck converters. Therefore, AHB converters are well suited for applications with a wide‐output voltage range, such as LED drivers, battery chargers, and USB‐PD chargers. This paper proposes an integrated dual‐module AHB flyback converter, which is composed of two AHB flyback converters. A dual‐resonant tank design effectively divides the input voltage, reducing voltage stress on the primary‐side switches. Additionally, the use of two transformers and secondary‐side rectifiers enables power and load current sharing, which mitigates current stress on the secondary‐side rectifying components. These features make the converter well suited for applications requiring a wide‐output voltage range and high‐output current. Compared to conventional AHB flyback converters, the proposed architecture demonstrates improved conversion efficiency. This study provides a detailed analysis and design of this new AHB flyback converter. A 360‐W prototype with a 380 V DC input, 24 V DC to 48 V DC output, and 72‐kHz switching frequency has been developed to verify the feasibility of the converter.