The rapid transition toward a converter-dominated power system, driven by high penetration of inverter-based resources (IBRs), the explosive growth of artificial intelligence (AI) technologies, and large power electronic loads, is fundamentally altering grid dynamics and exposing critical limitations in conventional stability, protection, and planning frameworks. Traditional metrics, such as the short-circuit ratio (SCR), have been shown to be insufficient for capturing impedance interactions, control coupling, and multi-timescale dynamics in such systems. This paper develops a unified, control-aware, and impedance-based modeling framework that accurately represents both grid-following and grid-forming behaviors. It highlights the increasingly active role of large-scale loads as grid-interactive resources with significant impacts on frequency and voltage stability, particularly in weak grids. In addition, battery energy storage systems (BESSs) are identified as a key enabler for providing fast dynamic support and mitigating variability across multiple timescales. A hierarchical assessment methodology combining system-strength screening, impedance-based stability analysis, Nyquist evaluation, and EMT-oriented validation is proposed to bridge conventional planning studies and converter-dominated system assessment. Key findings demonstrate that the reliable operation of future grids requires moving beyond steady-state and phasor-domain assumptions toward EMT-based validation, adaptive protection schemes, and coordinated grid-forming control strategies. The study further emphasizes the need for harmonized, performance-based grid codes to ensure the consistent integration of both generation and large loads. Overall, this work provides a comprehensive framework for the modeling, analysis, and control of inverter-dominated power systems, addressing critical gaps in current methodologies and supporting the secure evolution of modern power grids.
Hussein et al. (2026) studied this question.