Single-Phase Voltage Source Inverter With Voltage Boosting and Power Decoupling Capabilities

This article proposes a single-phase bridge inverter with both voltage boosting and power decoupling capabilities. The proposed inverter topology diverts the second-order ripple power into a small film capacitor instead of using a bulky electrolytic capacitor at the dc side, thus eliminating the large electrolytic capacitor that has a short lifetime. The voltage across the decoupling capacitor is controlled as a dc-biased sine wave to cancel out the second-order ripple power originated from the single-phase grid power, and the dc offset in the decoupling capacitor is used to boost the dc-link voltage, as opposed to being under-utilized in previous dc voltage-reference power decoupling techniques. The proposed topology also maintains the advantages of the traditional bridge inverters with the unipolar sinusoidal pulsewidth modulation technique. Moreover, the output filter and power decoupling control method are designed for the proposed inverter. Finally, the simulation and experimental results verify the feasibility of the proposed topology and control algorithm, which show successful voltage boosting and power decoupling functions.