Analysis and Design of a Novel Three-Phase Soft-Switching Rectifier

A novel power converter configuration of a three-phase soft-switching rectifier comprising four main switches and four auxiliary switches is proposed in this paper. The reduction in number of main switches can also increase the reliability because the control circuits and the auxiliary circuits are thereby reduced to two sets. All main switches in the proposed rectifier operate at zero voltage switching (ZVS) turn-on, while the auxiliary switches operate at zero current switching (ZCS) turn-off. Moreover, the proposed rectifier achieves a near unity power factor, sinusoidal input currents, a regulated output voltage and a bidirectional power flow capability. Finally, a small-signal model is derived and a feed-forward control is presented to achieve almost zero output impedance and zero audio susceptibility. Some experimental results of the proposed soft-switching rectifier, rated 400 W and operated at 40 kHz, are presented for verification.