Low voltage ride-through control strategy of a grid-forming inverter considering power decoupling

Grid-forming control is an important means for enhancing the stability of new power systems. The power coupling of grid-forming inverters can cause fluctuations in power, output voltage, and current, thereby affecting the low voltage ride-through (LVRT) capability of renewable energy. To address this issue, a LVRT control strategy for grid-forming inverters based on power decoupling is proposed. First, the power coupling mechanism under grid-forming control is analyzed. By establishing a dynamic power coupling model, the impact of power coupling on LVRT is studied. Subsequently, a power decoupling method based on a series compensation matrix is proposed, and an LVRT control strategy for grid-forming inverters considering power decoupling is developed based on grid-connection standards. Finally, a hardware-in-the-loop experimental platform is constructed using the StarSimHiL platform. The robustness of the series compensation decoupling control strategy with different impedance ratios, as well as the effectiveness of the proposed control strategy in various voltage sag conditions are verified through experiment. © 2024 Power System Protection and Control Press. All rights reserved.