On the sensitivity of power system dynamic modes to system parameters

Abstract The integration of inverter-based renewable energy sources reduces grid inertia and challenges power system stability, especially under structural disorder and parameter uncertainty. Traditional modal analysis, relying on system eigenmodes, lacks robustness in such conditions. This paper proposes a novel framework inspired by condensed matter physics, using scattering-based metrics—scattering time and mean free path—to characterize dynamic behavior in disordered power grids. Starting from simplified toy models and extending to realistic grids, we identify three regimes: ballistic, diffusive, and localized. Analytical results show that reduced inertia shortens scattering time, amplifying disorder effects. The cut-off frequency between regimes scales with grid size as ω c ∝ L −2/3 . Numerical simulations confirm theoretical predictions. This approach offers a robust alternative to perturbative methods for assessing dynamic stability in low-inertia grids with high renewable penetration.