Wind Risk Assessment of Electric Power Lines due to Hurricane Hazard

Abstract

This paper proposes a methodology to assess the wind risk of electrical transmission towers considering the coupling of the tower with the cables and a failure mechanism based on capacity. In the proposed methodology, the necessary steps to assess risk (hazard, exposure, vulnerability) and their geographic representation are presented. Wind hazard is briefly described considering hurricane events as the basis for the analysis of wind speed. The components of a transmission line are presented, and the forces acting over it are evaluated according to given specifications. The structural vulnerability of the tower is computed based on the damage levels that depend on the failure mechanism presented with different wind speeds incidences (0°, 45°, and 90°); these results are used to define the damage probability distribution. Finally, a case study of the expected losses computed with a probabilistic risk analysis for the transmission towers in Mexico is presented along with a more detailed analysis of the transmission towers between the Mérida and Lerma substations, reflecting the importance of the geographic location in the risk assessment.