Enhanced MPPT-Based Control Strategy for Single-Phase Grid-Connected Inverters in PV Systems

This paper presents a simulation-based study of a single-phase grid-connected photovoltaic (PV) system employing a maximum power point tracking (MPPT) method combined with a PI-controlled inverter. The proposed system utilizes the Gradient Descent (GD) MPPT algorithm and a well-designed LCL filter to achieve high tracking accuracy and reduce power loss. Three scenarios are analyzed: constant irradiance, sudden irradiance variation, and gradual irradiance change. Results show that the GD-based MPPT rapidly converges to the global maximum power point (MPP), while the PI controller ensures grid current synchronization and maintains a low total harmonic distortion (THD) of less than 3%. The system demonstrates reliable performance with stable power injection into the grid and minimal oscillations under dynamic environmental conditions. This study provides a feasible and effective solution for integrating distributed solar energy sources into the power grid.