Efficiency-Oriented Adaptive Dead Time Control for the Dual Active Bridge Converter

In the full bridge topology, dead time is a crucial parameter that directly affects the energy conversion efficiency and performance of the full bridge topology. Dead time is a period of time without output that is actively added to the control signal of the switching device. Its main purpose is to prevent the upper and lower switching tubes of the bridge arm from conducting at the same time, and to avoid the generation of huge current after short circuit, which may cause device damage. However, the addition of dead time inevitably introduces problems such as energy loss and waveform distortion, which cannot be ignored for DAB converters that pursue high efficiency. This paper will establish a mathematical model of dead time based on GaN HEMT driving circuit, and propose an adaptive dead time control strategy based on this model. The optimal dead time will be obtained through the current operating conditions for control, and finally simulation analysis will be conducted to verify the correctness and effectiveness of the proposed strategy.