Assessment of the resilience of transmission networks to extreme wind events

Extreme weather may have a significant influence on the resilience of transmission systems. However, modelling the impact of weather is very challenging due to its stochastic and unpredicted nature and behaviour. To cope with these challenges, this paper presents a Sequential Monte Carlo based time-series model for evaluating the effect of weather on power system components, with focus on the wind effect on transmission lines and towers, and in turn on the entire transmission power infrastructure. The concept of fragility curves is used, which express the failure probabilities of the components as a continuous function of the wind speed. The mapping of the wind profile on these fragility curves provides the weather-affected operational state of the transmission lines and towers at every simulation time step. The model is illustrated using a simplified 29-bus model of the transmission network of Great Britain (GB). The simulation results highlight and quantify how the GB test network becomes less resilient for extreme wind events, and the effectiveness of mitigation strategies such as network reinforcement or redundancy.