Analysis of the Fluctuation Band of the Boundary of the Stability Domain for the Wind Power Grid-Connected System Under Stochastic Disturbances

Following grid connection, stochastic disturbances may cause the boundary of stability domain (BSD) of wind power grid-connected system to deviate from a single deterministic curve. To characterize this uncertainty, this paper introduces a Wiener-process-driven local active power perturbation into the system model and proposes a fluctuation band of the boundary of stability domain (BSD-FB). Mean and mean-square stability conditions are derived to constrain the admissible disturbance intensity. Simulations on a two-machine equivalent system show that stochastic disturbances broaden the deterministic BSD into a band-shaped domain, and the conservative boundary can provide a robust reference for stability margin evaluation. The proposed method is intended for local uncertainty-aware margin characterization near the deterministic critical boundary, rather than a complete nonlinear transient stability criterion.