A probabilistic approach for analysis of line outage risk caused by wildfires

Abstract

Growing wildfire-related transmission and distribution line outages have become a severe problem and a main concern for some utilities. This manuscript aims to integrate wildfire risk with the vulnerability of overhead lines through a probabilistic approach where a combined line outage probability (CLOP) model is developed to calculate the risk of line outage. This method provides the combined probability of a line outage while taking several factors into account, such as dynamic heat balance-based aging failure, normally distributed voltage breakdown, and line tripping due to the change in conductor rating. The proposed probabilistic model yields improvement over existing methods, where only one factor is considered. In this regard, our simulation results show that the combined probability method calculates a 10–30% higher line outage risk compared to models where only voltage breakdown is considered and a 60–80% higher risk when only thermal aging is considered. This means that existing methods based on only one parameter are inaccurate and that the CLOP model developed in this paper leads to a more in-depth line-outage assessment of risk during wildfires, enabling us to perform long-term transmission scheduling with higher accuracy. In addition, the relationship between the line outage probability and the physical locations of lines and wildfire is established.