Transmission lines, crucial to the power grid, are subjected to diverse environmental conditions such as wind, temperature, humidity, and pollution. While these conditions represent a consistent impact on the transmission lines, certain unpredictable conditions such as unexpected high wind, wildfire, and icing pose catastrophic risks to the reliability and integrity of the transmission lines. These factors in the presence of initial damage and electrical loads greatly affect the material properties. In this paper, we develop a comprehensive thermo-electro-mechanical model to investigate the long-term effect of unexpected high wind, wildfire, and ice on transmission lines. This study offers an in-depth perspective on temperature and damage evolution within the power lines by incorporating a phase field model for damage and fatigue, alongside thermal and electrical models. We define a state function to assess the failure, considering damage and temperature. We study three scenarios deterministically to establish a basic understanding and analyze the stochastic behavior using the Probabilistic Collocation Method (PCM). We utilize PCM for forward uncertainty quantification, conducting sensitivity analysis, and evaluating the probability of failure. This approach offers an in-depth examination of the potential risks associated with transmission lines under unfavorable circumstances.

翻译：输电线路作为电网的关键组成部分，长期承受风、温度、湿度和污染等多种环境条件的影响。尽管这些条件对输电线路构成持续作用，但某些不可预测的极端条件——如突发强风、野火与覆冰——会对输电线路的可靠性与结构完整性带来灾难性风险。这些因素在初始损伤与电气载荷共同存在的情况下，会显著影响材料性能。本文建立了一个综合的热-电-力学模型，以研究突发强风、野火与覆冰对输电线路的长期效应。通过结合损伤与疲劳的相场模型以及热学与电气模型，本研究深入揭示了电力线路内部的温度演变与损伤演化过程。我们定义了一个考虑损伤与温度的状态函数来评估故障。首先对三种场景进行确定性研究以建立基础认知，随后采用概率配置法（Probabilistic Collocation Method, PCM）分析其随机行为。我们利用PCM进行前向不确定性量化、开展敏感性分析并评估故障概率。该方法为深入探究输电线路在不利环境下的潜在风险提供了系统分析框架。