A novel high efficiency soft-switched PWM boost rectifiers with low conduction losses

A high efficiency soft-switched Boost voltage-doubler Converter for Power Factor Pre-regulator is proposed in this paper. The topology can perform soft-switching in the two main switches and the passive switches, and zero-current switching in the auxiliary switch. Furthermore, soft commutations of the two main switches are achieved without additional current stress by the presented PWM soft-switched auxiliary circuit. A significant reduction in the conduction losses is achieved, since the circulating current for the soft switching flows only through the auxiliary circuit and a minimum number of switching devices are involved in the circulating current path, and the proposed rectifier is suit for low line input and high power applications. Computer simulation and a prototype rated at 600 W, operating 50 kHz, with an input AC voltage of 120 Vrms and an output voltage of 400 Vdc has been implemented in the laboratory. A high efficiency up to 97% and power factor over 0.997 has been measured.