@article{Sun2026, 
author = {Jiadong Sun and Xiangyang Xing and Rui Zhang and Zhiyuan Meng},
title = {Mechanism Analysis and Advanced Control for Virtual Synchronous Generators under Weak Grid Conditions during LVRT},
year = {2026},
journal = {Chinese Journal of Electrical Engineering},
volume = {12},
number = {1},
pages = {306-319},
keywords = {Virtual synchronous generator, virtual impedance, LVRT strategy, transient stability, overcurrent suppression, post-fault performance},
url = {https://www.sciopen.com/article/10.23919/CJEE.2025.000112},
doi = {10.23919/CJEE.2025.000112},
abstract = {Virtual synchronous generator (VSG) is a grid-friendly converter that can effectively support the grid and operate stably in a weak grid. However, VSGs are susceptible to grid voltage sags, which may induce overcurrent and transient instability due to their synchronous generator-like properties. In particular, as grid strength decreases, the output capacity of the VSG is reduced, making transient instability a more severe issue than overcurrent when a voltage sag occurs. Transient instability poses a threat to power system security and stability. To address these issues, a mechanism analysis and an advanced control strategy are proposed for VSGs operating under weak grid conditions during low-voltage ride-through (LVRT). First, the factors influencing transient stability are analyzed. Second, the characteristics of LVRT-related issues in weak grid conditions are examined. Finally, an advanced LVRT control strategy and a novel virtual impedance (Ⅵ) structure are proposed to maintain transient stability and suppress overcurrent. Benefiting from this strategy, transient stability is improved, and the post-fault period is expected to be short and smooth. Simulations and experiments are conducted to verify the effectiveness of the proposed approach.}
}