Reduced-switch three-phase active power filter with one cycle control

This paper presents a design for a three phase active power filter using a reduced switch (B4) topology and one-cycle control. The B4 topology offers the advantage of reduced cost and bridge losses at the expense of increased DC-side voltage and device stress. This design also provides the advantages associated with one-cycle control. This constant frequency switching technique requires neither load VAR calculation nor reference waveform generation and the control circuit is simple. Through analysis and simulations, the feasibility of the design and essential differences from a similar design reported in the literature are examined. A laboratory prototype has also been built and the experimental filter is able to compensate low power factor loads and suppress harmonic currents.