The optimal ratio of grid-forming (GFM) to grid-following (GFL) inverters ratio are not well studied in literature with regards to system resiliency and reliable power delivery. This paper provides an analytical approach using the aggregated models of GFM and GFL inverters to determine their optimal ratios and minimize their adverse dynamic interactions in response to disturbances. The main objective of this paper is to provide a comprehensive dynamic interaction analysis for the fleet of GFM and GFL inverters within a grid cluster and the impact of inertia level emulated by these inverters on power electronics dominated grid (PEDG) resiliency. The provided analysis is validated via several case studies in large-scale simulation and a small-scale experimental testbed representing a grid cluster with multiple GFM and GFL inverters. This digest presents a summary of the proposed analytical approach for optimizing grid resiliency.
