Digitally controlled three-phase power factor correction circuit with partially resonant circuit

This paper presents the three-phase PFC (power factor correction) circuit with partially resonant circuit using a DSP (digital signal processor). The power supply systems for telecommunication and data communication systems have been able to get the high power factor and low input current harmonic distortion factor using the PFC circuit. However, the PFC circuit requires many components and many adjusting processes especially in case of the three-phase input PFC. In this paper, the advantages of the digital control with DSP are shown and compared with the analog control. With the digital control using DSP, better regulation of the output voltage, fewer components and reducing adjusting process are achieved. Also the partially resonant circuit which is effective to the PFC circuit is also shown. In the partially resonant circuit, both the main switches and the resonant switches switch under soft switching conditions. Over 97% efficiency of the PFC circuit is realized in the 2.5 kW power supply system.