Contribution to the Study of the Performance of Z-Source Converters

The fact growing for advanced control strategies in Distributed Generation (DG) systems by harnessing the potential of Z-source inverters (ZSIs) and quasi-Z-source inverters (qZSIs) as a powerful type of Impedance Source Inverter (ISI). To achieve this, the research explores four key objectives. Firstly, a comparative analysis through simulations evaluates the ability of ZSI/qZSI with switched-inductors to boost voltage, considering factors like voltage gain and component count. Secondly, a comprehensive review assesses existing modulation techniques for ZSI/qZSIs. Thirdly, a novel three-dimensional space vector modulation (3DZSVM) technique specifically designed for four-leg qZSIs (4L-qZSIs) is introduced. This method improves overall performance, particularly in steady-state operation and reduced harmonic distortion. Finally, a novel simplified predictive direct power control (PDPC) strategy for grid-tied photovoltaic (PV) systems using qZSIs is proposed. This method operates with a fixed switching frequency and achieves superior power tracking and grid integration. The research presented here, substantiated by detailed explanations, analyses, and simulation results, advances the development of ZSI/qZSI control for DG systems, paving the way for their wider adoption in building robust and efficient renewable energy integration solutions