Improved Performance of a Two-Stage Converter Topology Using Incremental Conductance-Based MPPT Design for Grid-Tied PV Systems

A DC-DC converter is used between the PV modules and the inverter in a two-stage grid-integrated photovoltaic (PV) system. The dynamic interactions between the maximum power point tracking (MPPT) controller, inverter, and DC-DC converter may affect the system's performance. This grid-connected system model integrated the MPPT mechanism to maximize the output power of the photovoltaic array, regardless of the temperature, irradiation conditions, and load characteristics. The PV system's output voltage is regulated using a control technique with multiple inputs. The multiple input controller accommodates the high-frequency switching action in the inner loop, and the PI controller in the outer loop is designed to improve the dynamic performance. The proposed incremental conductance MPPT-based two-stage converter topology is designed and simulated with MATLAB Simulink simulation tool to validate the enhanced performance and analyzed power quality of the current injected into the grid. The performance analysis of the proposed system indicates that the closed-loop performance can be improved in several ways, including a faster response with less overshoot.