In traditional views, the build-up of accelerating energy during faults can cause the well-known first-swing angle instability in synchronous generators (SGs). Interestingly, this letter presents a new insight that the accumulation of decelerating energy due to the low voltage ride-through (LVRT) and recovery control of grid-following inverter-based resources (GFL-IBRs), might also result in transient angle instability in SGs. The transient energy accumulated during angle-decreasing swing transforms into the acceleration energy of the subsequent swing, hence such phenomena often manifest as multi-swing instability. Both theoretical analysis and simulation support these findings.
@article{arxiv.2603.25167,
title = {Multi-Swing Transient Stability of Synchronous Generators and IBR Combined Generation Systems},
author = {Songhao Yang and Bingfang Li and Zhiguo Hao and Yiwen Hu and Huan Xie and Tianqi Zhao and Baohui Zhang},
journal= {arXiv preprint arXiv:2603.25167},
year = {2026}
}