Abstract:
This work presents a control scheme to control a grid-connected single-phase photovoltaic
(PV) system. The considered system has four 250 W solar panels, a non-inverting buck-boost DC DC converter, and a DC-AC inverter with an inductor-capacitor-inductor (LCL) filter. The control
system aims to track and operate at the maximum power point (MPP) of the PV panels, regulate the
voltage of the DC link, and supply the grid with a unity power factor. To achieve these goals, the
proposed control system consists of three parts: an MPP tracking controller module with a fuzzy based modified incremental conductance (INC) algorithm, a DC-link voltage regulator with a hybrid
fuzzy proportional-integral (PI) controller, and a current controller module using a linear quadratic
regulator (LQR) for grid-connected power. Based on fuzzy control and an LQR, this work introduces
a full control solution for grid-connected single-phase PV systems. The key novelty of this research is
to analyze and prove that the newly proposed method is more successful in numerous aspects by
comparing and evaluating previous and present control methods. The designed control system settles
quickly, which is critical for output stability. In addition, as compared to the backstepping approach
used in our past study, the LQR technique is more resistant to sudden changes and disturbances.
Furthermore, the backstepping method produces a larger overshoot, which has a detrimental impact
on efficiency. Simulation findings under various weather conditions were compared to theoretical
ones to indicate that the system can deal with variations in weather parameters.