ABSTRACT
Predicting the occurrence of failures in power grids through specific outage risk predictors is a primary concern for utilities nowadays. Wooden poles represent core items to focus on in this process. Millions of them are used worldwide and they are all subject to the risk of crack formation. Analyzing the evolution of pole cracks is particularly relevant in reliability analyses of power grids for two main reasons. First: the cracks might highlight previously unconsidered or changing factors, such as unusual local weather conditions (e.g. overload of ice and/or wind). Second: as cracks provide an access for external threats (e.g. humidity, fungi, insects) to potentially non-treated internal parts of the poles, they might in turn accelerate the occurrence of further failures. Evaluating the role of crack formation is thus essential for estimating the risk of outages in power grids. As climatic variations are known to be among the most influencing factors in the initiation and propagation of cracks in wooden poles, we address this topic by suggesting a method combining open-access weather-data sources with information provided by new technologies, such as drones. We first highlight the influence of climatic factors on the reliability of wooden poles by reviewing studies describing the physical properties of wood. We then focus our research on a Norwegian case study and show how we can combine up to 60 years of meteorological information with the information provided by 17,352 geo-localized aerial pictures of cracked and non-cracked wooden utility poles. We finally discuss the way an indicator constructed on this combination can be used to predict the formation of cracks and optimize the allocation of decision-maker resources for inspection procedures.
