Reduced-order passivity-based sliding mode controller for quazi Z source inverter

Abstract

This study focuses on the development of robust control strategies for a photovoltaic system integrated with a grid-connected quazi-Z-source inverter (qZSI). Conventional current control methods, such as proportional–integral (PI) controllers, often fail to maintain satisfactory performance under system uncertainties. In practical grid-connected operation, qZSI systems are subjected to disturbances including direct current-link voltage fluctuations, load variations, and fault conditions, which restrict the inverter’s operating range. To address these challenges, robust control techniques are employed to enhance system stability and extend the operational range under uncertain conditions. The main novelty of this work lies in the design and implementation of a reduced-order passivity-based sliding mode controller (ROP-SMC) that explicitly accounts for system uncertainties while reducing controller complexity, and its systematic comparison with conventional PI and H∞ controllers under identical operating conditions. Simulation results demonstrate that the proposed ROP-SMC provides superior robustness and performance compared to conventional control approaches under various operating scenarios.