Experimental and numerical analysis of overhead transmission lines vibration due to atmospheric icing

Atmospheric icing is one of the main threats to overhead transmission lines in cold regions. The ice related loads may cause mechanical incidents, such as wire breakage, cable rupture, clamp slipping, cross-arm deformation and even tower collapse. Ice shedding may lead to dramatic vibration of lines and cause flashover or short circuit among ground wires, conductors and the earth. Therefore, to obtain the static and dynamic load characteristics of the overhead electric transmission lines is essential for transmission line design and operation. Also, it provides important information for health evaluation of transmission line components, and prediction of their remaining service life. In present study, a three-span full scale physical model of transmission line was established, with the span length of 50m-150m-50m. Ice shedding was simulated by sudden release of lumped mass. The mid-span jump heights were measured during different ice shedding scenarios, to quantizing the dynamic characteristics of lines. Then, finite element method (FEM) was employed for numerical simulation of ice shedding phenomenon. The comparison of numerical and experimental results confirms the feasibility and efficiency of the numerical simulation method in this paper. This study provides essential experimental data about ice shedding of full scale transmission lines, and is of great help for transmission line design and icing disaster alleviation.