A soft-switching dual-phase-shift controlled full-bridge converter with voltage-doubler for wide voltage range applications

A soft-switching full-bridge converter (FBC) with dual-phase-shift control strategy is proposed for high efficiency conversion in wide voltage range applications. The proposed FBC can be operated either in step-up mode or step-down mode. Secondary-side phase-shift control is employed for the step-up mode, while primary-side phase-shift control is adopted for the step-down mode. Zero-voltage-switching (ZVS) is achieved for both the primary and secondary-side power devices in a wide load and voltage range due to unique structure of the proposed converter and the dual-phase-shift control scheme. The reverse recovery problem of rectifier diodes is eliminated, which helps to achieve high efficiency. The leakage inductance of the transformer is utilized to achieve the power transfer and thus the voltage spike caused by the leakage inductor is removed. The voltage stresses across the primary-side and secondary-side MOSFETs are clamped to the input voltage and half of the output voltage, respectively. The operational principle analysis with experimental results is provided to verify the effectiveness and advantages of the proposed converter.