Single-stage buck-boost inverter with feedforward control

The off-grid inverter with the inverter side voltage as the feedback parameter has the advantages of a single voltage loop, simple control parameter design, and low cost. But the output voltage accuracy is not enough. A single-stage off-grid inverter with feedforward control is recommended to improve the output voltage accuracy. It has a higher voltage regulation rate compared to the proportional-integral (PI) control and it can track a given AC signal at any frequency compared to the proportional-resonant (PR) control. Bus capacitors can employ thin-film capacitors for improved reliability and higher power density and the voltage stress on power devices can be decreased by controlling the intermediate bus voltage to a non-constant value. The working principle is explained. The design principles of the parameters are provided and the external characteristics and stability of the system are analyzed. A simulation model was built to verify the control strategy for improving voltage accuracy and decreasing voltage stress. (c) 2023 The Author(s). Published by Elsevier Ltd. This is an open access article under theCCBY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).