As part of the research project "Fuchstal leuchtet," building on previous findings from LINDA 2.0, the investigation focuses on how stable grid operation can be ensured in a purely inverter-based island grid. For this purpose, system operation is controlled using only the grid variables of voltage and frequency, reflecting interconnected grid behavior through the use of grid-forming and grid-following inverters. Within this paper, parameter settings and test scenarios based on manufacturer-specific RMS simulation models are developed to analyse the influence of outer-loop P(f)- and f(P)-control strategies of grid-forming and grid-following inverters on frequency behavior. By implementing various parameter scenarios and corresponding grid disturbances within the simulations, the study identifies which critical interactions can be revealed using RMS-simulation models. Based on these findings, it is evaluated whether stable island grid operation is possible using the applicable technical connection rules (TCR) for grid-following generation units and whether adjustments may be necessary. Therefore, parameter variations of grid-forming and grid-following inverters are analyzed regarding their impact on frequency dynamics and system stability in the island grid.
Weinmann et al. (Sun,) studied this question.