This paper presents an updated frequency response model for converter dominated power systems. This model considers the impact of the grid-forming and grid- following converters penetration on the frequency response in power systems. To this end, the proposed frequency response model is constructed of the aggregated synchronous generators, grid-forming, grid-following systems, and their interactions. The characteristics of the aggregated systems are captured by their inherent properties, and their interaction is designed to obtain a comprehensive frequency response. To validate the proposed model, extensive tests are conducted using the IEEE 39-bus power system in the Simulink/MATLAB environment.
