SLYT835 March 2023
A control method allows PSFB converter to work with active snubber under peak current mode control is discussed in this paper. The active snubber allows lower voltage stress on the output rectifier with negligible power dissipation on the snubber circuit that greatly improves converter efficiency. The current disturbance introduced by the active snubber makes peak current mode control difficult. With the active snubber power switch on-time fixed and frequency reduction control implemented, a high efficiency and peak current controlled PSFB converter can be realized. A 400Vin, 12Vout/3kW PSFB prototype is built with the proposed control method has been verified across whole operational load range with output rectifier voltage stress limited below 40 V at 250A full load.