Modelling the vulnerability of overhead lines against tree contacts for resilience assessment

The contact of overhead lines with vegetation represents a significant cause of failures, also as secondary effects of weather events such as strong wind, ice/snow accumulation. Thus, the management of the right of ways (ROW) of overhead lines is a key aspect to improve grid resilience. This paper proposes a probabilistic vulnerability model of overhead line failure due to inadvertent contact with vegetation, supporting the assessment of loss of load risk. The model can help TSOs to plan vegetation trimming campaigns and to alert operators in case of extreme weather events. Simulations on a realistic electric system demonstrate how the vulnerability model identifies the areas subject to tree fall. Moreover, its application within a resilience assessment methodology allows to relate the load interruption risk with both weather conditions (wind and snow loads) and deviations from ROW management standards.