GFL-GFM Dual-Mode Predictive Control of Power Converters for Stiffness-Varying Power Grids

As the penetration of the offshore wind energy increases rapidly, the impedance of offshore collector fluctuates more widely, which leads to significant grid stiffness variations. This raises large challenges to system stability and power integration efficiency of grid-tied power converters, adopting classical grid-following control techniques, which perform properly solely when grid stiffness is high. In this work, a grid-following and grid-forming dual-mode predictive control for grid-tied power converters is proposed. The proposed method is more suitable for large changes of grid impedance, i.e., large grid stiffness variations. Finally, the proposal's validity has been substantiated by the simulation data.