Stability Limits and Improved Robustness of Grid-Forming Converters With External Inertia-Emulation Loop

An external inertia emulation loop (IEL) prevents instability in grid-forming converters during frequency disturbances. This paper investigates IEL stability limits and compares three alternatives to improve IEL performance under power limitation. Simulations confirm the IEL’s robustness and the effectiveness of the proposed solution in avoiding undesired active-power injection at the disturbance end.