Comparison for Mechanical Properties of Transmission Towers in Uniform and Non-uniform Icing Condition under Micro-Topography

Transmission towers may collapse because of ice accretion on transmission lines, which seriously threatens the safe and stable operation of power system. Digital twin can reflect the operation state of the device. The combination of finite element simulation, digital twin and online monitoring is helpful to realize the intelligent operation and maintenance of device. A 110 kV transmission lines under the micro-topography was taken as the research object in this paper. In the context of digital twin, a transmission tower-line system model with three-tower-two-line was established by finite element simulation. The mechanical properties of tangent tower and tension tower in uniform icing condition were compared and analyzed. It was found that the tangent tower was seriously stressed. The mechanical characteristics of the tangent tower under the conditions of uniform icing and non-uniform icing (including heavy iced on the short span and heavy iced on the long span) were simulated under a total of 27 operation conditions. The distribution of axial stress and nodal displacement were obtained. The mechanical characteristics of the transmission tower under the condition of uniform and non-uniform icing were compared and analyzed. The results showed that the axial stress may decrease first and then increase in the case of heavy iced on the short span of the tower. Compared with the heavy iced on the short span, the axial stress change rate of the tower with the long span is greater. Compared with uniform icing, non-uniform icing would increase the axial stress and nodal displacement of the towers, and increase the damage risk of the towers.