Finite Element Modelling Approach to Assess Fatigue of Composite OHL Conductors

Electricity utilities are obliged to developing renewable energy strategies, and electrification of energy sectors to reduce fossil fuels footprint. To accommodate this trend, utilities try to avoid the expensive solution of building new overhead lines and reinforce existing networks through re-conductoring with bigger size conductors or making use of novel designs such as High- Temperature Low-Sag technologies. The effect of conductor structure and material properties on its vibrations and fatigue responses have not yet been captured thoroughly in literature. In this respect, a Finite Element Model has been established in COMSOL Multiphysics to examine the fatigue performance of the composite structure of OHL conductors. To validate the model, simulation results are compared against the standard Poffenberger- Swart theory. The presented work have shown that the vibration and fatigue of bi-metallic conductors is not a linear problem and the assumption of a homogeneous structure does not apply to all conductor sizes. The internal structure of the conductors must be considered rather than a simplified homogeneous assumption especially for multi-layered conductors. The results also showed that trapezoidal conductors experience less fatigue compared to round designs. The FEM analysis are limited to the efficiency and power of used computing resources.