Analysis and design of an auxiliary commutated full bridge DC/DC converter topology including the effect of leakage inductance

This paper presents the analysis and design of an auxiliary commutated full bridge DC/DC converter topology including the effect of leakage inductance of the output transformer. In applications where the transformer has high turns-ratio between the primary and secondary windings, the value of leakage inductance is relatively high. This high value of leakage inductance, however, is not large enough to achieve the zero voltage switching (ZVS) of the converter over the entire range of operating load conditions, but can be effectively used in minimizing the circulating current of the auxiliary commutation circuit used for achieving ZVS. The operating principle of the circuit is demonstrated and the steady state analysis is performed. Based on the analysis, a criterion for optimal design is given.