A Soft Switching of the Three-level Neutral Point Clamp Isolation Bidirectional Converter

This paper proposes a new type of three-level neutral point clamp isolated bidirectional Dc-Dc converter (3L-NPC IBDC). The proposed converter can significantly improve the power factor, and can achieve a high-voltage and high-efficiency as well. In this work, a detailed analysis the relationship between the phase and duty cycle of the transmission power and output voltage of the presented 3L-NPC IBDC converter. Furthermore, the operating range of the zero-voltage switching (ZVS) is emphatically investigated for both modes. An improved efficiency of 3L-NPC IBDC is accordingly achieved by reducing the switching loss with ZVS. A corresponding simulation model and experimental platform are then set up to demonstrate the corrections of the presented theoretical analyses, and the simulated and experimental results explicitly verify the performance predicted by the theoretical analyses.