Minimum Leakage Inductance for Soft-switching of Dual-Active Half-Bridge DC-DC Converter

In DC-DC converters like Dual Active Bridge (DAB) and Dual Active Half Bridge (DAHB) where leakage inductance also acts like power transfer inductance, it is important to have optimum leakage inductance, especially in high frequency applications. High value of leakage inductance result in high RMS current through transformer with higher conduction losses in transformer and switches, whereas, low value of leakage inductance result in loss of Zero Voltage Switching (ZVS) turn-on at lower power level with higher switching losses. This paper presents analytical derivation of minimum leakage inductance and dead-time for ZVS turn-on of switches in Current Source Voltage Source (CSVS) type of Dual Active Half Bridge (DAHB) DC/DC Converter which can be used to design optimal leakage inductance.