Soft-switching modulation for boost full bridge converter with active clamp circuit

This paper presents an improved soft-switching modulation for boost full bridge converter with active clamp circuit. The active clamp is used to achieve the zero voltage switching (ZVS) operating conditions for the clamp itself and the full bridge. Thanks to the ZVS property, the converter can be used with high switching frequency, improving the power density. Moreover the boost circuit allow to reduce the transformer voltage ratio and to work with wide variation of input and load. The active clamp driving logic has been modelled with Finite State Machine (FSM) and can be easily made with classical digital circuit logic. The mathematical analysis was verified with PLECS simulations.