Multi-Swing Transient Stability of Synchronous Generators and IBR Combined Generation Systems
This addresses a potential stability problem in power systems with combined generation, offering a new insight but appears incremental as it builds on known instability mechanisms.
The paper identifies that low voltage ride-through and recovery control of grid-following inverter-based resources can cause transient angle instability in synchronous generators, leading to multi-swing instability, as supported by theoretical analysis and simulation.
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.