Study on the Dynamic Characteristics of Tensional Force for Ice Accumulated Overhead Lines Considering Instantaneous Wind Speed

Abstract

Icing is one of the key factors affecting the security and reliability of power system operation. Ice accumulation on the overhead line (OHL) conductors is often accompanied by strong winds, whose magnitude and direction are varied constantly, which imposes challenges to the on-line monitoring of OHL’s ice load. This paper analyzed the dynamic characteristics of the tensional force for ice accumulated OHLs through both the on-site experiment and the finite element method (FEM). The correlation between the instantaneous wind speed, the thickness of the accumulated ice and the dynamic tensional force, the aerodynamic resistance coefficient of the conductor, is investigated. It is found that the axial dynamic tension at the end of the iced conductor is approximately proportional to the square of the instantaneous wind speed. The higher the wind speed, the larger the difference between the static tension and the maximum dynamic tension calculated using the 10-min average wind speed. Under the conditions of the example in this article (crescent-shaped icing), when the average wind speed is 20 m/s, the ratio of the difference to static tension is 11.19%. These conclusions are verified with the computational fluid dynamic (CFD) simulation, the same correlation is identified in comparison with the experiments. Due to the fact that the magnitudes of tensional force and vibration are determined by the instantaneous wind speed, significant error exists within traditional calculation methods where average wind speed is used instead.