FPGA-in-the-loop simulation of a grid-connected photovoltaic system by using a predictive control

Currently, the use of Field Programmable Gate Array (FPGA) devices as control platforms is common in areas where real-time control is important, as renewable energy system. Grid-connected photovoltaic systems require control strategies to optimize the performance of the complete system. This article presents the implementation of a control strategy on a FPGA platform working with a single-phase grid-connected photovoltaic system developed in MATLAB/Simulink environment. The control strategy of the system consists of a variable-step MPPT algorithm with a predictive current control to operate a boost converter on the first stage. In the second stage, a simplified active and reactive power control ensures that the maximum power is transferred to the grid trough a cascaded H-bridge multilevel inverter. A single-phase PLL based on the PQ theory is used to track the frequency of the grid. The results obtained in the simulation allow to validate the proposed strategy.