The analysis and evaluation for the leakage inductance effects of two front-end Dc/Dc converters with capacitive output filter

Nowadays, with the rapid development of the consumer electronics, the power density of the power supply adapter is going to be much higher. To reduce the voltage stress on secondary-side rectifiers and the secondary-side conduction loss, the capacitive output filter is widely used, in the half-bridge LLC resonant converter and in the soft-switched phase-shift full-bridge converter with primary-side energy storage inductor for instance. However, compared with the inductance output filter, the capacitive output filter usually leads to relative large output current ripple, which makes the secondary-side leakage inductance of transformer suffer from the considerable volt-second balance. Thus, the practical voltage stress on the secondary-side rectifier should be considered more carefully. This paper shows the detailed analysis and evaluation for the leakage inductance effects of two front-end Dc/Dc converters with capacitive output filters. Some design considerations are also given for the engineers.