Stability region and radius in electric power systems under sustained random perturbations

•Stability Region and Radius are defined for Stochastic Linear Systems.•Stability via Lyapunov exponents is performed in multimachine Power Systems.•The Ornstein–Uhlenbeck process is used to model stochastic random perturbations in time.•Lyapunov Exponents are used to compute the Stability Region and Radius in Power Systems.

Two concepts are proposed to characterize the behavior of stochastic systems under sustained random perturbations in time: Using Lyapunov exponents we define the region where an electric power system can be operated under random perturbations without losing stability; and we characterize the maximum perturbation size that a system can sustain. The proposed methodology is applied to international test systems of nine and thirty-nine buses.