In the field of grid-connected photovoltaic power generation

the cascaded grid-connected converter shows great development potential

thanks to its capability to boost power generation efficiency under uneven illumination. However

independent maximum power point tracking(MPPT)regulation in each sub-module can lead to DC bus voltage imbalances

undermining system stability. Thus

when controlling grid-connected current

DC bus voltage balance must also be considered

turning the control strategy into a multi-objective challenge.To tackle this

a multi-objective finite control set model predictive control method(FCS-MPC) is proposed for a two-stage photovoltaic cascaded grid-connected converter. This method establishes prediction models for grid-connected currents and DC bus voltages across different switch states. By incorporating PI control and a cost function design in model predictive control

it simultaneously achieves grid-connected current regulation

total DC bus voltage maintenance

and voltage balance among DC buses.A nine-level cascaded H-bridge(CHB)photovoltaic converter model was built in MATLAB/Simulink to test system performance under various conditions. Simulation results show that the proposed method ensures excellent steady-state operation and dynamic response.