Sufficient Conditions for Robust Frequency Stability of AC Power Systems

This paper analyses the frequency stability of ac grids in presence non-dispatchable generation and stochastic loads. Its main goal is to evaluate conditions which system robust large, persistent active power disturbances without recurring time-domain simulations. Considering ongoing energy transition more renewable sources, defining robustness boundaries a key topic for planning operation. However, much research on long-term studies has not dealt with dynamic constraints, while short-term usually depend time-consuming simulations nonlinearities. To bridge this gap, authors derive an algebraic equation that provides sufficient systems relationship among four quantities: maximum perturbation, minimum damping, steady-state transient limits. achieve goal, it uses nonlinear average-model grid Lyapunov's direct method extended by perturbation analysis requiring only limited knowledge parameters. The calculations are validated using IEEE 39-bus test results compared traditional Swing Equation model.