An approach to harmonic-free AC/DC power conversion for large industrial loads: the integration of a series active filter with a double-series diode rectifier

This paper proposes a new harmonic-free AC/DC power converter characterized by the integration of a small-rated series active filter with a large-rated double-series diode rectifier. The DC terminals of the series active filter are directly connected in parallel with those of the double-series diode rectifier, thereby forming a common DC bus. The series active filter enables the diode rectifier to draw three-phase sinusoidal currents from the utility. In addition, it can provide the supplementary value-added function of regulating the common DC bus voltage to a limited extent of ±5%, with slightly increased RMS voltage rating but without increasing peak voltage rating. Experimental results obtained from a 5 kW laboratory system verify the practical viability and cost-effectiveness of the proposed AC/DC power converter