AC to DC power conversion with unity power factor and sinusoidal input current

The authors present a one-stage single-phase controlled rectifier which has a wide output variation on the DC output maintaining unity power factor and sinusoidal current on the input side. The scheme consists of four bilateral switches, a high-frequency transformer, and a diode rectifier bridge with low-pass filters on both ends. This scheme also provides galvanic isolation, which is required in most industrial applications with a transformer of small size compared to the ones used with the phase-controlled converters. Three control strategies for the operation of the converter are proposed and verified experimentally. The harmonic spectra on the AC side are analytically derived, and its low frequency harmonics up to half of the switching frequency or higher orders have been eliminated, depending on the control strategies