CCM PFC Research Articles

A 500 Watts Single Stage Single Switch Soft Switched CCM PFC Flyback Converter with BCM Control

Single stage isolated AC to DC converters find prominence due to simplicity and efficiency in addition to economics. Boundary control Mode BCM Flyback converters are widely used for such applications up to power levels of 200 watts. For higher power levels, average current control mode PFCs are used and two stage conversion is incorporated. In this paper, a novel technique for building a single stage PFC with a Continuous Conduction Mode CCM Flyback AC DC converter is proposed for 500 watts power. A practicalsingle stage converter is built with power factor correction and input output isolation. The unique feature of the new configuration lies in having only one primary MOSFET switch and adapting BCM control in a CCM Flyback configuration and achieving ZVS and ZCS while in CCM operation. Proposed configuration is best suited for battery charger applications. Also, the absence of high voltage bulk capacitor at the mains input adds lot of advantages in terms of eliminating inrush current and saving PCB area. A working model of 130 V Dc output and 4.0A is built and the test data are presented depicting the complete soft switching of all power devices and exhibiting the efficiencies in excess of 95%.

Loss and conducted noise characteristics for CCM PFC circuit with SiC-Schottky barrier diode

Loss and conducted noise characteristics for CCM PFC circuit with SiC-Schottky barrier diode

A High Performance CCM PFC Circuit Using a SiC Schottky Diode and a Si SuperFET<sup>TM</sup> Switch

SuperFETTM MOSFETs and silicon carbide (SiC) Schottky diodes are applied to continuous conduction mode active power factor correction pre-regulators. SuperFETTM MOSFETs can reduce power losses dramatically with their extremely low RDS(ON) and fast switching. The SiC Schottky diode has virtually zero reverse recovery current and high thermal conductivity, and is close to an ideal diode for a CCM PFC circuit. Due to these outstanding switching characteristics, frequency can be increased. In this paper, the SiC Schottky diode’s and SuperFETTM MOSFET’s performance have been verified in a CCM PFC boost converter. These products can reduce the total power losses and enhance the system efficiency.