As distributed generation becomes more prevalent in the electric power system, it is essential to analyze the generation mix and associated technologies to ensure resilient and stable grid operation. In particular, the increased share of grid-following versus grid-forming generation can pose serious grid stability issues and needs to be carefully evaluated. This study employs the Modelica open-source modelling framework to conduct dynamic simulations on a medium-voltage distribution network model where demand is primarily served by local distributed generation. In order to increase scalability, the complexity of the distribution network model is reduced to an equivalent reduced-order model that preserves the dynamic behavior of the original detailed system. Various penetration scenarios of conventional grid-following converters versus distributed synchronous generators are investigated. The scenarios are examined during sudden load disruptions of varying magnitudes, similar to observed events such as the 2021 Texas power crisis or the 2003 East Coast blackout. The results reveal that, in scenarios with a high penetration of grid-following converters, grid stability is significantly compromised. In particular, penetrations greater than 80% lead to disconnection of all converters during severe load increases.
Ungerland et al. (2026) studied this question.