Enhancing Frequency Stability in Low-Inertia Power Systems Through Distributed Grid-Forming Inverters

The increasing penetration of Renewable Energy Resources within Electrical Power Systems is progressively reducing the number of traditional synchronous machine units, posing significant challenges to frequency stability. To address this issue, Grid-Forming inverters paired with energy storage systems, have emerged as a promising technology for providing support in low-inertia power systems. Through advanced control strategies and the fast response of energy storage units, these devices emulate the behavior of synchronous machines, actively providing support to the frequency stability of power systems. This paper analyzed the effectiveness of distributed grid-forming inverter architectures. The results highlight that configurations relying on multiple grid-forming units exhibit superior frequency stabilization characteristics compared to setups in which inverter-based generation operates in a purely grid-following mode. Leveraging the proposed control algorithm, the distributed inverters can contribute to frequency regulation while also track power references. The proposed approach has been validated through time-domain simulations conducted on a distribution network under various inertia conditions and disturbances scenarios. The outcomes demonstrate that replacing grid-following units with gridforming units can deliver significant improvements in frequency support and resilience in system characterized by high penetration of renewable generation.