The computational mechanics group at SRK Argentina embarked on an in-depth analysis of the impact of broken conductors on transmission lines. This initiative was part of a collaborative effort with the Electric Power Research Institute (EPRI) to support their full-scale investigations. Given the prohibitive costs associated with physical testing, the use of Finite Element Method (FEM) tools offers a cost-effective and efficient alternative for understanding the behavior of transmission lines under such conditions.
The primary objective of this project was to simulate the instantaneous shock load generated when a conductor ruptures. This shock load propagates through the conductor at the speed of sound in the material, which is approximately 4500 m/s (10,000 mph) for metallic conductors. The axial shock wave can reflect at the end of a tension section, potentially affecting strain structures some distance from the rupture point. To quantify this impact, a dynamic load factor was defined.
The analysis was conducted using ADINA 9.10 software, chosen for its capability to accurately replicate the non-linear behavior of the system. The model accounted for damping effects, including the inherent axial damping of the conductor and the aerodynamic effects of the wind.
The project successfully validated the FEM tool by comparing its dynamic analysis results with real-scale test data, demonstrating a high degree of accuracy. An automated script was developed to streamline the creation of input files for ADINA and to post-process the results through plots. Sensitivity analysis was performed by varying key parameters such as span length, insulator length, and support stiffness. This analysis provided valuable insights into the interplay between these variables and the resulting peak load or dynamic load factor.
The findings, illustrated in the project profile, highlight the effectiveness of the FEM tool in replicating real-world conditions. The results showed a good agreement between the test data and the simulations, thereby offering a reliable method for predicting the impact of conductor ruptures on transmission lines. This project not only enhances our understanding of the dynamic behavior of transmission lines but also provides a robust framework for future investigations and practical applications in the field.
