Modeling the OHL vulnerability to strong wind

Extreme weather events are a major concern for Transmission System Operators (TSOs) because of their increasing frequency and disruptive effects on system infrastructure and load supply. Modelling the component vulnerabilities to natural threats is a fundamental pillar to face such events in a resilience perspective. In particular, advanced analytical models of component vulnerability to threats have an important advantage over statistical models: being less sensitive to classification errors, they may favour the development of approaches and tools to support operators’ choices in power system management. Among all natural threats, strong wind represents a very important cause of damages to HV and EHV lines, together with wet snow, in the Italian EHV grid. This paper proposes analytical models to simulate the vulnerability of overhead lines to the direct and indirect effects of strong wind, considering three major subcomponents of the line namely phase conductors, shield wires, and tower supports. Simulations performed on a set of HV and EHV lines from a portion of the Italian grid demonstrate the ability of the model to quantify the benefit of specific mitigation measures on the line vulnerability to strong wind.