Investigation of Ice Accretion Conditions in Observed Galloping Events of Four-Bundled Conductor

Ice accretion characteristics and the relationship between ice accretion and tension fluctuations caused by galloping were investigated based on 28 icing events observed in the test line located on a mountain ridge in Japan. The details of three significant ice accretion and galloping events that were well available from the data and photographs regarding ice accretion were discussed. Observation results showed that ice accretion grows when the temperature ranges from -2.0 to -0.5 degrees C. It melts at a temperature above -0.5 degrees C or a humidity beneath 100%. The wind speed during galloping is greater when the ice accretion height is greater. Additionally, galloping becomes less steady when the ice accretion shape is rougher. The average tension correlates well with the ice accretion amount during no galloping and weak wind conditions. Building a method for removing the influence of wind from the average tension is also important for estimating the ice accretion amount of the event without weak wind.