Fault-Chain-Based Prevention and Control Method for Typhoon Disaster

Extreme disasters such as typhoons pose a great threat to the operational integrity and stability of power grids, making pre-disaster preventive and control measures increasingly important. Motivated by the limitations of conventional N-1 and N-2 security criteria in addressing spatially correlated and probability-driven failures, this paper proposes a fault-chain-based prevention and control method for typhoon disasters. A typhoon wind field model is combined with a transmission branch vulnerability model to quantify the spatiotemporal failure probabilities of transmission branches, based on which high-risk branches under forecast typhoon scenarios are identified. Taking these branches as initial contingencies, a systematic fault chain search is performed to enumerate critical cascading outage paths, and a risk index is established by integrating the failure probabilities at each stage with the corresponding load shedding. On this basis, a risk-oriented preventive control optimization model is formulated, in which generator outputs and load shedding are coordinated to minimize the expected consequences of high-risk fault chains while satisfying operational constraints. Case studies on the IEEE 39-bus test system and the Hainan power grid under Typhoon Yagi verify that the proposed method can effectively capture typhoon-induced failure characteristics, significantly reduce expected load curtailment, and alleviate excessive control costs compared with traditional deterministic criteria. The results demonstrate that the proposed method provides a practical and economical decision-support tool for online operation of power grids under extreme typhoon conditions.