I'm working on a DC/DC converter. For isolation and increment of voltage, I used HF transformer with two half bridge in both sides. When I switching both half bridge with the same switching pattern(zero phase shift), it should be flowing zero power, but power flows in both direction and it depends on the voltage of two sides!
anyone can analyze this?
In an ideal dual active bridge DC/DC converter with phase shift modulation and no phase shift there is no active power flow.
In reality the dead time needed to prevent a shoot-through will introduce a phase shift that will change according to the voltages applied on the two bridges. You can find more information in this paper: Article Power Flow Characterization of a Bidirectional Galvanically ...
@ Milad M.H.Khani :
thank you for your answer.
yes, you are true. for more accurate answer, I should say, I find that if dead time be longer or duty cycle be below 50% ( i.e. 45% (5% without any pulse)), system will be in discontinues mode and regular DAB transfer power formula is not true.
After a while, and some research I found that my converter works as an LLC Resonant Converter actually. The LLC Resonant Converter work principle is simple but different from the DAB converter (with the nearly same topology). In the attached paper, these converters are compared in detail.