Performance study of photovoltaic generator with a three-level NPC inverter linked to the grid

This research is designed to analyze an elaborated model of a grid-linked photovoltaic (PV) system based on a controlled DC/DC boost inverter and the multilevel neutral point-clamped (NPC) inverter. The modeling of the system is established to be able to carry out a frequency analysis. Then, the synchronization of the converter to the network is ensured by a phase-locked loop (PLL). The regulation strategy ensuring stability and robustness is presented. Particular attention will be paid to the sizing of the elements of the control. The obtained results show the effectiveness of voltage and current correction, and their synchronization with the network, and show that the THD is in compliance with the prevailing standards under variable climate conditions. The converter is able to operate under abnormal voltage and frequency conditions, its response in fault conditions is fast, and the steady state does not suffer from any static error. All simulations have been realized in MATLAB/Simulink environment.