A Three Windings Full Bridge Converter with a Lossless Clamp Circuit (original) (raw)

For high output voltage and high power full bridge converter with wide range of input voltage, the secondary rectifier diodes in a traditional clamp circuit suffer fr om too high voltage stress. A three windings full bridge converter with a lossless clamp circuit is proposed in this paper. The converter achieves that the upper limit of input voltage is more than twice as high as the lower limit, and the voltage stress of the rectifier diodes is effectively clamped to the output voltage. Firstly, the calculation formula of rectifier diode voltage stress is derived. Secondly, the problems in the present clamp circuit are analyzed. The working principle of the proposed clamp circuit is elaborated in detail. Theoretical analysis is carried out to optimize the secondary windings' turn ratio to achieve the wide range of input voltage. A 300W prototype is developed to verify the validity of the theoretical analysis. Finally, the PSPICE simulation results show the proposed three winding...