Efficient Hybrid Dual Full-Bridge DC–DC Converters for Pulsed Output Current Applications

This article presents a hybrid full-bridge for high efficiency in a wide output voltage range, especially for pulsed output current applications. For the conventional phase-shift full-bridge dc–dc converter, the hard switching and circulating current lower the efficiency in the wide output conversion ratio. To improve the efficiency of the dc–dc power supply for the pulsed output current, a hybrid dc–dc converter is proposed. On the primary side, two full bridges are integrated by sharing a bridge leg. The circuit on the secondary side is a hybrid rectifier stage. For the pulsed output current with a constant load resistor, a single full bridge works in a low output current. For the large output current, the hybrid two full bridges work together. The circulating current in the hybrid working mode is reduced by a blocking capacitor. The converter is controlled by phase shift and duty cycle control. All the switches work in zero-voltage switching. A prototype is built to verify the performance and control strategy of the converter.