Abstract: Photovoltaic（PV）power generation is an important power generation method to achieve the goal of

carbon neutrality. During the grid connection of PV power generation system，due to the characteristics of inverter

and the influence of nonlinear load，high-order harmonics are generated，the power quality of the power grid is

reduced，and the safe operation of the power generation and grid system is affected. To solve this problem，the

topology of grid connected inverter was optimized. Using three-level inverter，multi-level can effectively improve

the harmonics generated in the process of grid connection. Aiming at the harmonics generated at the load side，

harmonic detection was carried out at the common connection node，and the power quality at the load side was

improved at the same time of grid connection. Model predictive control（MPC）was used to control the grid

connection process. Finally，the proposed structure and control method were verified in Matlab/Simulink toolbox.

The results show that in the case of harmonic pollution，the PV grid connected power quality control system based

on finite control set model predictive control（FCS-MPC）can not only inject maximum power into the grid，but

also compensate the harmonics generated by the nonlinear load of the grid，reduce the harmonic content，and make the total harmonic distortion（THD）of the power grid meet the power grid standard.

      Key words: photovoltaic（PV）power generation；power quality；three-level inverter；harmonic control；

model predictive contro（l MPC）