Theoretical algorithm for maximum jump height of the conductor after ice-shedding considering elevation angle and nonlinearity

Abstract

The determination of maximum jump height of the conductor in ice zones is extremely important for the design of transmission line. Considering the elevation angle and nonlinearity, the theoretical formulas for maximum jump height of the conductor after ice-shedding is derived. Based on the catenary equation theory, simplified models of a single span horizontal and inclined conductors following ice-shedding are built using the same and different two suspension points respectively. Regarding ice-shedding of the conductor as a sudden loading, the energy conversion equation about the maximum jump height is established based on the energy method. Combined with the cable structure theory, the formulas for maximum jump height of the horizontal and inclined conductor are presented. Additionally, finite element method (FEM) was carried out with software Ansys on a single span horizontal and inclined conductor under different span length, initial stress and mass ratio ice-conductor.The accuracy of the presented formulas was verified by the results of maximum jump height for simulated conductors. Finally, error analysis is conducted considering the nonlinear change of dynamic tension. And some formulas are revised according to the reasons of errors.The calculated results of revised formulas match the FEM analysis results better, thus the accuracy of these formulas is improved. The given formulas establish the quantitative relationship between the maximum jump height and the sag of the conductor, maximum sag difference in midspan, the dimensionless frequency and the mass ration ice-conductor. The presented formulars for maximum jump height meet the engineering design requirement and provides theoretical guidance for conductor lines design.