Analysis and design of a novel single-phase soft-switching active power filter

This study proposes a novel single-phase soft-switching active power filter (SSAPF) using a simple resonance unit. All main switches in the proposed SSAPF operate at zero-voltage-switching (ZVS) turn on, while the auxiliary switches operate at zero-current-switching (ZCS) turn off. The advantages of the proposed power filter include improved efficiency, reduced voltage stresses, and greatly reduced EMI. Moreover, the proposed SSAPF achieves a sinusoidal line current and a near unity power factor. Finally, we present a simple feedforward control to improve the transient performance of the proposed SSAPF. A prototype hardware circuit was constructed, and some experimental results are presented for verification.