Research on low voltage ride-through control strategy of grid-forming PV-BESS converters based on voltage limitation

Grid-forming (GFM) photovoltaic battery energy storage (PV-BESS) systems have seen extensive deployment within renewable energy systems, owing to their remarkable attributes of operational agility and robust adaptability to weak grids. However, the fault ride-through capabilities of conventional GFM PV-BESS remain relatively feeble. When the voltage fault occurs in the grid, the grid-connected converters are highly prone to overcurrent. Therefore, considering the outer features of the electric potential source of the converters in grid-forming PV-BESS systems, this paper proposes a novel voltage-limitation-based low voltage ride-through (LVRT) control applicable to grid-forming PV-BESS systems. This method can still maintain the grid-forming characteristics of the PV-BESS systems during faults and achieve the limitation of fault currents. Ultimately, the validity of the control strategy put forward is validated through simulations.