Probabilistic system failure assessment of transmission tower lines in a changing climate

This paper presents a probabilistic framework for modelling cascading structural failures in electric power transmission tower lines subjected to wind hazard events in a changing climate. Recognizing the limitations of treating towers as isolated components, the study incorporates interdependencies among towers due to mechanical connectivity through conductors. The proposed model captures both the randomness of initial tower failures caused by wind and the subsequent correlation and clustering of tower failures resulting from structural imbalances. System-level fragility functions are derived from finite element simulations and fitted using probabilistic distributions. The transmission line system is modelled as a sequence of regular towers, with initial failures occurring independently. The failure patterns segment the system into intervals, where cascading is modelled as a stochastic process influenced by proximity to failed towers and load redistribution. An advanced virtual modelling technique combined with analytical expressions are proposed to analyse the probability distributions and generating functions of clustering of tower failures. Such that for different transmission tower line systems, the total potential failed towers and probabilities can be predicted directly under strong wind hazards. Outcomes are used for assessment on climate change risks and impacts for a large-scale transmission tower line network, which provides the foundation of decision support for climate change adaptation planning.