A novel ZVS synchronous boost converter with coupled LC auxiliary circuit
摘要
In this paper, a novel zero-voltage switching (ZVS) synchronous rectification (SR) boost converter with a coupled inductor-capacitor (LC) circuit is proposed. This ZVS SR boost converter employs a transformer (coupled inductor), a capacitor, an inductor, and a diode as the ZVS auxiliary circuit. The new auxiliary circuit utilizes an LC resonant circuit as the energy source and uses a coupled inductor to generate a unidirectional triangular wave current from this energy source, thereby providing ZVS conditions to the main switch of the boost converter. The detailed operating principle, soft-switching limitations, voltage, and current stress are presented. Moreover, the proposed converter is compared with the existing soft-switching DC/DC converters to verify its superiority. Finally, a 300 W experimental prototype is developed, and the key waveforms and efficiency are measured. The experimental results are consistent with the theoretical analysis. They also show that both transistors of the proposed converter can operate under ZVS conditions. The peak efficiency of the proposed converter reaches 97.24%.