Research on LVRT Control Strategy of New Energy-Storage Hybrid Grid-Connection Power System on Grid-forming Converters

To address the LVRT(low voltage ride-through) problem in renewable energy and energy storage integrated grid-connected systems under grid-forming converter control, this paper proposes an improved control strategy based on the conventional LVRT approach by introducing an additional voltage limiter. The traditional strategy is first analyzed, revealing the risk of synchronism loss under prolonged fault conditions, and indicating that current limiting alone is insufficient to ensure system stability. To overcome this limitation, a voltage-limiting mechanism is introduced to enhance the suppression of fault currents and improve the system's synchronizing stability over extended time scales. A simulation model is developed on the MATLAB/Simulink platform to verify the effectiveness of the proposed strategy. Simulation results demonstrate that, under a three-phase symmetrical voltage sag, the proposed method successfully maintains the grid connection of the renewable energy and storage system, significantly enhancing its fault ride-through capability and operational stability.