Dead-Time Effect of the High-Frequency Isolated Bidirectional Full-Bridge DC-DC Converter: Comprehensive Theoretical Analysis and Experimental Verification

As the development of isolated bidirectional full-bridge dc-dc converter (IBDC), the dead-time effect has become an apparent issue. This paper presents a comprehensive theoretical analysis and experimental verification of dead-time effect in the IBDC. Besides the internal power transfer and phase drift phenomena mentioned in previous works, there are also many other novel phenomena caused by the dead time, such as voltage polarity reversal and voltage sag phenomena, etc. The paper gives a detailed switching characterization of the IBDC with dead-time effect in all operation states. On this basis, the transmission power characterization is analyzed comprehensively. Compared to the traditional theoretical model, the transmission power model with dead-time effect is not a strictly monotone increasing function, the relation curve is not symmetric around the median axis, and the zero point is not achieved at zero phase-shift ratio. In addition, in different operation states, the characterization is also different. Finally, experimental results verify the theoretical analysis.