Digital Deadbeat Control of Three Phase Quasi-Z Source Inverter /

Abstract

Renewable energy sources, especially PV systems, are the most preferable source of energy production due to their availability on a large scale and less production cost. The significance of inverters grows as inverters regulate the flow between green energy sources and the grid power system. Control methods are essential in resolving problems related to the spread of renewable energy, such as keeping electricity quality, safeguarding against the discovery of islanding, and maintaining the stability of the system. This thesis discusses a digital deadbeat control (DDC) technique for the three-phase quasi-Z-source inverter (qZSI). The proposed control approach aims to regulate the qZSI's output current and voltage with quick dynamic response against the disturbances, to improve the quality of waveform when system undergoes linear and non-linear load conditions and to minimize the contents of harmonic distortion. DDC has an inner current loop, an outer voltage loop and a state observer to generate a deadbeat response. Observer estimates the state parameters of the system to make the output response of the system more dynamic against the uncertainties caused by the output load and unpredicted external disturbances. A numerical simulation is performed to verify the theoretical developments of this paper. The results are presented that demonstrate the effectiveness of the proposed system. Due to the accurately calculated parameters, the recommended method is more effective to make the system more robust and is shown by simulation results. The designed system's stability factor is in accordance with IEEE (American Institute of Electrical and Electronic Engineers) standard 519-2022.