Improved PFC Circuit for Three-Phase Single Switch Having Auxiliary Capacitors

Nonlinear rectifier circuits, having capacitors or inductors, are generally used as rectifier circuits, such as those in consumer electronics and appliances. It is known that such rectifiers generate various harmonics in the power system. To reduce these harmonic problems, various original PFC (Power Factor Correction) circuits have been proposed. Amongst these, Prasad-Ziogas, et al, have proposed a PFC scheme using single switching device for three phase circuit applications. This method achieves a PFC effect by simultaneously creating three phase supplies by the use of a single switch through an inductor. On the basis of this scheme, we propose an alternative PFC circuit. This method attempts to improve the input current, approaching a nearly sinusoidal waveform, by using an intermediate capacitor circuit, with a method of operation analogous to the conventional method having capacitor filter, but is, nonetheless, original. Various fundamental operations have been considered and have been confirmed by computer simulation. Compared with the conventional Prasad-Ziogas circuits, the construction is a little more complicated, but the output power can be much increased, in addition to improved THD (Total Harmonic Distortion).