Effects of Conductor Temperature and Conductor Angle on Icing of Overhead Power Line Conductors During Atmospheric Icing Events

Makkonen [1] model, we combine controlled Climatic Wind Tunnel experiments with field measurements from four transmission line towers in winter 2024/2025 to calibrate ice-load simulations. Results indicate that collision efficiency remains approximately constant during accretion but consistently exceeds predictions from the standard Finstad model. Field data support an effective efficiency of approx. 0.24, aligning with cylindrical rime accretion theory but suggesting the Finstad [2]model underestimates real-world values. Furthermore, accretion is shown to be largely invariant for inflow angles between 45° and 90°, with significant mass reduction occurring only below 45°. This contradicts ISO 12494 [3], which posits a stronger sine-squared reduction at moderate angles. Finally, conductor temperature acts as a binary boundary condition. Icing initiates only when the conductor surface drops below 0°, after which the insulating effect of the initial layer renders subsequent fluctuations irrelevant to growth rates. Incorporating these revised parameters enables more accurate site-specific simulations, supporting optimized capital allocation and improved infrastructure reliability.