Sammendrag
The single-stage grid-connected photovoltaic (PV) topology has drawn attention in the recent years as it can reduce the overall losses and installation costs. However, an efficient control is necessary to operate such a system satisfactorily. This paper presents a new control approach for single-stage grid-connected PV systems. The proposed controller is a combination of a finite control set model predictive control (FCS-MPC) and a maximum power point tracking (MPPT) algorithm, which ensures the extraction of maximum power from the PV panels and good transient performance of the output voltage and current. The disadvantages of classical MPPT algorithms in tracking the global maximum power point under fluctuating environmental conditions are avoided by including additional constraints in the cost function of the FCS-MPC. The effectiveness of the proposed controller is shown by a comparative study with the standard two-stage PV configuration. Further, the controller performance is tested for the partial shading in PV. The results show that the single-stage PV system with the proposed control can effectively extract the maximum power from the PV system and maintain a stable output signal through all the transient condition. Finally, experimental results are presented to validate the effectiveness of the proposed algorithm.