Study on Galloping Oscillation of Iced Twin Bundle Conductors considering the Effects of Variation of Aerodynamic and Electromagnetic Forces

Abstract

Due to the occurrence of whole-span and subspan vibration at the same time during the galloping of the iced bundle conductors, the distance between the subconductors changes, resulting in the variation of the aerodynamic parameters for the leeward subconductors. The existing conventional studies usually only consider the whole-span galloping, ignoring the relative motion and the electromagnetic force between the subconductors. Based on considering the above two factors at the same time, a new numerical simulation method to study the galloping behaviors of the iced conductors is presented. Then, the galloping behaviors of the iced twin bundle conductors’ transmission line with different current intensity, initial wind attack angle, and spacer layout are studied. The galloping oscillation behaviors include time histories of vibration displacements, mode, amplitude, frequency, motion traces, and the distance between two subconductors. The simulation results showed that the whole-span and subspan vibration appear at the same time during galloping oscillation and two subconductors may collide with each other when affected by the varying electromagnetic and aerodynamic forces. The effects of varying electromagnetic and aerodynamic forces on galloping behavior cannot be ignored. The new method presented in this work can contribute to the galloping study of the iced bundle conductors.

Theoretical Analysis and Experimental Validation on Galloping of Iced Transmission Lines in a Moderating Airflow

“…On one hand, these tests mainly focused on the aerodynamic coefficients with different cross-sectional shapes [17,18], ice thicknesses [19], wind attack angles [20,21], and crosssection areas [22]. On the other hand, the tests were mostly performed on a truncated conductor model [23,24], which cannot accurately reflect the galloping profiles of different galloping modes; however, conductor galloping involves a hybrid vibration of different modes, which may even show different responses to the declining wind velocity. erefore, galloping of the iced transmission line subjected to a moderating wind field is analysed, and a wind tunnel test is performed on a continuous conductor model in this study.…”

Study on Adaptive Excitation System of Transmission Line Galloping Based on Electromagnetic Repulsive Mechanism

“…Remarkable achievements have been made from a lot of research on galloping mechanisms [4][5][6], experiments [7][8][9][10], numerical simulation [11][12][13][14][15][16][17][18][19], antigalloping devices, and field monitoring [20] carried out by researchers around the world. In terms of galloping numerical simulation, Desai et al [12,13] decomposed galloping into lateral motion and torsional motion, established a two-degree-of-freedom galloping model, and analysed the galloping response of the bundled transmission line.…”

Prediction model for aerodynamic coefficients of iced quad bundle conductors based on machine learning method

“…Braun & Awruch [ 11 ] proposed a numerical model for the aerodynamic and aeroelastic analysis of bundle conductors. The group of the authors of this paper numerically determined the aerodynamic coefficients of a quad bundle conductor accreted with crescent-shaped ice [ 12 ] and those of iced twin bundle conductors varying with relative location between two sub-conductors [ 13 ] using a two-dimensional model by the Fluent software. Ishihara & Oka [ 14 ] computed the aerodynamic coefficients of single and quad bundle ice-accreted conductors using the large-eddy-simulation (LES) turbulence model and presented the correction coefficients for the leeward sub-conductors to reflect the wake influence.…”

“…Figure13. Structure of prediction model for aerodynamic coefficients of iced quad bundle conductors.…”