A model predictive control for low-frequency ripple power elimination of active power filter integrated single-phase quasi-Z-source inverter

A model predictive control (MPC) is proposed for a buck-type active power filter (APF) integrated single-phase quasi-Z-source inverter (qZSI) to directly eliminate the dc-side low-frequency ripple power. The buck-type APF operates independently from the main circuit power devices, comparing to the coupled-type APF. The proposed MPC compensates the low-frequency ripple power directly by the APF capacitor power and achieves fast responses during load power changes. There is no requirement to preset the capacitor voltage, thus to easily handle the non-linear loads. With the proposed solution, the APF is able to freely divert the dc-side low frequency (not only double line frequency) ripple power to the APF's capacitor in the form of highly fluctuated voltage and current, so as to decrease qZS inductance and capacitance. The buck-type APF is analyzed and the proposed method is illustrated. Simulation results demonstrate the validity of the proposed approach.