Design of a power factor correction ac-dc converter

The need to keep EMI emissions by electronic power supplies below the limit specified by international standards have dictated that any new power supply design must include active power factor correction at the front end. The modern trend in power supply designs is towards digital control. This paper reports an effort to design a power factor correction AC-DC converter that is geared towards digital control. The power factor correction circuit employs zero voltage transition arrangement to minimize switching losses. Calculations that led to the selection of the circuit components are presented. Interface requirements between the power converter stage and the digital control processor are tackled. Average current mode control method is employed in the controller. The complete design has been tested by means of Powersim power electronics simulation software. The resulting input voltage and current waveforms show that the design is successful.