Reliability Assessment of Electrical Grids Subjected to Wind Hazards and Ice Accretion with Concurrent Wind

Abstract

The supportive structures of power grids are vital but susceptible to weather-related events, such as extreme wind and icing rain with concurrent wind. The objective of this paper is to assess the reliability of the power grids subjected to high wind and ice accretion. The material and geometry uncertainty and the strength deterioration of poles due to decay are included in probabilistic models considering the bending failure of the poles and tensile failure of the wires. The extreme wind speed and icing accretion thickness are modeled with the Weibull distribution and generalized Pareto distribution, respectively. The fragility and reliability are analyzed with a Monte Carlo simulation for the comparison of two example locations with different hazard conditions. Case studies are implemented with a notional system and the system of Centerville, a fictitious study domain. The results illustrated that the fragility of wires is noteworthy in icing hazard reliability assessment. During icing rain, the concurrent wind speed significantly impacts the reliability of the power grids. The system reliability subjected to wind hazards is more sensitive to pole strength deterioration than in icing scenarios. The presented analysis framework will be beneficial for the design and maintenance of power grids subjected to both wind and icing hazards.