Study on the Influence of Supply-Voltage Fluctuation on Shunt Active Power Filter

Is there any influence of supply-voltage fluctuation on the shunt active power filter? Few papers have discussed this problem. In this paper, based on the instantaneous power balance of shunt active power filter ac-side and dc-side, a small-signal model of dc-link voltage control is derived. According to this small-signal model, the influence of supply-voltage fluctuation on the dc-link voltage of shunt active power filter is analyzed in detail. The conclusion is that the supply-voltage fluctuation has influence on the dc-link voltage of shunt active power filter. Then a feedforward control method of supply-voltage and compensation current is proposed to eliminate the influence. The proposed feedforward control method can be easily implemented in practical. In this paper, the influence of supply-voltage fluctuation on compensation performance of shunt active power filter is also analyzed when the dc-link voltage is constant. From the analysis, it can be concluded that current controller with PI regulator has better performance to suppress the influence of the supply-voltage fluctuation. Finally, the experimental results are given to demonstrate the conclusions.