Current-Oriented Phase-Locked Loop Method for Robust Control of Grid-Connected Converter in Extremely Weak Grid

This letter presents a new phase-locked loop (PLL) control method for enhancing the synchronization stability of grid-following voltage-source converters in very weak grid conditions. This can be conveniently implemented without additional efforts on hardware and retains the existing PLL structure and current controller parameters. The proposed PLL method is competitive and effective for stability in emerging power systems with a high penetration of inverter-based resources. The effectiveness of the proposed method is confirmed through mathematical proofs and down-scaled experiments.