Photovoltaic Grid-Tied VSI Control Considering Parameter Uncertainty Based on DOB

In this paper, a photovoltaic grid-tied VSI was controlled based on a disturbance observer (DOB) approach. The proposed technique integrates a conventional control method with the disturbance observer. External disturbances and parameter uncertainty are estimated using DOB based on auxiliary variables. This method helps to increase the system's robustness and makes it possible to design the controller with the desired dynamics using the nominal model. The simulation results in MATLAB/Simulink confirm the validity of the proposed method.