Design Optimization of High Frequency Transformer for Dual Active Bridge DC-DC Converter

This paper presents a design optimization procedure for high frequency transformer (HFT) employed in bidirectional dual active bridge (DAB) isolated DC-DC converter. It is shown that leakage inductance, phase-shifted angle, skin and proximity effects have to be taken into account together with the HFT voltage-ampere rating to minimize total losses. It is also demonstrated that the leakage inductance required for zero voltage switching operation can be realized under the proposed design procedure without employing extra inductor. The proposed design methodology is experimentally validated by measurements on a prototype HFT.