A Nonlinear Sliding Mode Controller for Three-Phase Single-Stage Grid-Tied Photovoltaic System

A nonlinear sliding mode control (SMC) strategy is proposed in this paper for a three-phase, single-stage, grid-tied photovoltaic (PV) system. The controlled system consists of a photovoltaic generator (PVG), a three-phase voltage source inverter, a grid filter, and a balanced three-phase electrical grid. The controller seeks to accomplish three key objectives: (1) maximize power extraction from the PVG; (2) sustain a unity power factor on the grid side; and (3) guarantee the asymptotic stability of the closed-loop system. A sliding mode control technique is applied to the nonlinear system model formulated in the d-q synchronous reference frame. Theoretical stability analysis and simulation outcomes provide strong validation that the proposed control strategy effectively fulfills all predefined objectives.