Study and Simulation of SAPF Interconnected to a PV System Based on DPC with Disturbance Rejection Principle

This paper deals with a double-stage grid-connected photovoltaic (PV) system, associated with a shunt active power filter in order to supply the extracted photovoltaic power to the utility and to improve the power quality in the presence of nonlinear loads. The rejection of disturbances affecting to the grid is offered by the improved direct power control (DPC). This DPC command combines a proportional-integral (PI) for the regulation of the continuous bus voltage with an intelligent algorithm of tracking the maximum power point (MPPT) based on fuzzy logic, reserved to solve the problem of the rapidly decreasing or increasing irradiance. On the grid side, an improved DPC is developed to eliminate the unwanted harmonics induced in the functioning of the source currents. The overall control of presented system has been the object of an exam under different states of the power source behavior: distorted, unbalanced and balanced by simulation using MATLAB/Simulink software. The obtained simulations results demonstrate the robustness, feasibility and performance of these control strategies compared to the existing methods in the literature.