Risk-triggered preventive islanding for cascading failure mitigation and resilience enhancement in typhoon-prone power systems

Extreme weather events such as typhoons pose escalating threats to power system security by inducing multiple contingencies and large-scale blackouts. This paper presents a risk-triggered preventive islanding strategy designed to mitigate cascading failures and strengthen system resilience. The proposed strategy proactively disconnects transmission lines most susceptible to failure propagation once a system-level risk index surpasses a predefined threshold. First, a vulnerability model is established to characterize transmission line fragility under typhoon impacts. Second, a hierarchical risk indicator and triggering mechanism are developed to guide timely preventive actions. Next, constrained spectral clustering is employed to identify vulnerable node groups, and an optimization model determines the critical disconnections required for preventive islanding. Case studies on benchmark systems, including the 29-bus Great Britain transmission network, verify the strategy’s effectiveness in containing cascading failures and reducing outage scope under extreme conditions. • Component failure model capturing typhoon dynamics. • Multi-scale risk framework fusing physics and data. • Preventive islanding strategy using IWCSC algorithm. • RTPI strategy effectively limits fault propagation. • Unified framework coupling prediction and control.