A simple AC-DC PWM full-bridge converter with integrated power-factor correction

A simple ac-dc pulsewidth-modulation (PWM) converter that can perform isolated dc-dc conversion while shaping the input current to improve power factor is proposed in this paper. The converter is almost the same as a standard PWM full-bridge converter with a diode rectifier/LC low-pass filter input except for some slight modifications. The converter topology is, therefore, very simple, as is the method of control used to achieve both power-factor correction and dc-dc conversion. In the paper, the operation of the converter is explained and analyzed, and the converter´s steady-state characteristics are discussed. A design procedure for the selection of components is presented, and then demonstrated with an example. The feasibility of the converter, and its ability to meet EN61000-3-2 Class D standards for electrical equipment is shown with results obtained from an experimental prototype.