Two-Stage Preventive Control for Transient Voltage Security in Sending-End Power Systems with High Wind Power Penetration

To enhance wind power integration capability and voltage regulation performance in renewable energy-dominated sending-end power systems, this paper investigates a coordinated two-stage transient voltage stability control strategy combining wind farms with energy storage systems. In the first stage, an optimal power flow (OPF) model is formulated for grid steady-state operation, aiming to minimize the operational costs associated with energy storage utilization and wind power curtailment. The interior point method is implemented to solve the convex optimization framework and obtain the optimal steady-state operating condition. In the second stage, during the transient voltage stability control phase, a dynamic constraint-satisfaction model incorporating transient voltage security margins is developed to regulate post-optimization power flow deviations. The particle swarm and beetle antennae search technique are subsequently adopted to iteratively refine the operating point through intelligent swarm-based parameter adjustment. The effectiveness of the proposed two-stage preventive control framework is validated through electromagnetic transient simulations on a modified Nordic test system integrated with high-penetration wind generation, demonstrating measurable improvements in renewable energy accommodation capacity and transient voltage security indices under contingency scenarios.