Dynamic Behavior of Transmission Conductors Under Rupture Conditions Through Finite Element Modeling

Abstract

Understanding the dynamic behavior of transmission conductors under rupture conditions is a critical factor in ensuring the reliability and safety of power transmission systems. This is commonly studied by analyzing the dynamic load factor (DLF), which is a measure of the loads experienced by the system. This study investigates the impact of conductor properties on DLF through extensive finite element modeling and sensitivity analyses using the ADINA software by Bentley Studios. These finite element models carefully consider both internal (i.e. axial and lateral) and aerodynamic damping in the form of damping parameters, as these greatly influence the dynamic behavior of the models. Initially, simple models with a single conductor span were analyzed to understand the effects of span length, conductor stiffness, and catenary constants on DLF. Two examples are shown, which mimic full-scale tests conducted at the Dynamic Impact Test Line at the EPRI High Voltage Laboratory. After calibrating the FEM modeling parameters, the FEM results show high agreement with the full-scale test results. Following additional tests, a comparison of DLF vs. suspension structure stiffness is made, which indicates that higher suspension structure stiffness generally increases the DLF of both suspension and strain structures with less impact at higher stiffnesses. Subsequently, the scope was expanded to include multi-span configurations containing multiple suspension structures. An example is shown where the number of suspension structures ranges from 1 to 20. These results indicate that the effect of multiple suspension structures on DLF is complicated, likely due to the reflection of shockwaves between structures. This study provides valuable insight into the relationship between broken conductors and the resulting transmission line behavior, allowing engineers to mitigate risks when designing power transmission networks.