Analysis and implementation of ZVS forward converter with centre-tapped rectifier

Abstract

The system analysis and circuit implementation of a ZVS forward converter with centre-tapped rectifier are presented. To reduce the voltage stress of the active switch in the forward converter, one auxiliary switch and one clamp capacitor are used in the adopted converter to recycle the energy stored in the transformer leakage. The resonant circuit based on the output capacitance of switches and leakage inductance of the transformer will achieve zero-voltage-switching turn-on for both switches in the adopted converter to increase the total circuit efficiency. The centre-tapped rectifier is used at the secondary side to achieve full-wave rectifier. In high output current applications, the synchronous rectifier can be used in the secondary side to further reduce the conduction losses of rectifier diodes. The operating principles of the adopted ZVS forward converter with centre-tapped rectifier are analysed in detail. The design consideration and circuit example of the ZVS forward converter are presented. Finally, experimental results based on a ZVS forward converter with 5 V/16 A output load are provided to verify the effectiveness of the adopted converter compared with the asymmetrical half-bridge converter