Galloping Stability and Wind Tunnel Test of Iced Quad Bundled Conductors considering Wake Effect

Xiaohui Liu,Mengqi Cai,Chuan Wu,Guangyun Min,Ming Zou,Shuguang Yang

doi:10.1155/2020/8885648

Xiaohui Liu, Mengqi Cai + Show 4 more

Open Access

https://doi.org/10.1155/2020/8885648

Copy DOI

Abstract

A new quad bundle conductor galloping model considering wake effect is proposed to solve the problem of different aerodynamic coefficients of each subconductor of iced quad bundle conductor. Based on the quasistatic theory, a new 3-DOF (three degrees of freedom) galloping model of iced quad bundle conductors is established, which can accurately reflect the energy transfer and galloping of quad bundle conductor in three directions. After a series of formula derivations, the conductor stability judgment formula is obtained. In the wind tunnel test, according to the actual engineering situation, different variables are set up to accurately simulate the galloping of iced quad bundle conductor under the wind, and the aerodynamic coefficient is obtained. Finally, according to the stability judgment formula of this paper, calculate the critical wind speed of conductor galloping through programming. The dates of wind tunnel test and calculation in this paper can be used in the antigalloping design of transmission lines.

Highlights

Under wind load, self-excited vibration of iced transmission lines with low frequency and large amplitude occurs
We believe that the shape and thickness of the ice on the transmission line are constant along the conductor direction
In research, considering wake effect, the dynamic model of the 3-DOF iced quad bundled conductor is established to accurately reflect the galloping of the conductor. e wind tunnel test accurately simulated the galloping of iced quad bundled conductor under wind load. e stability criterion is used to calculate the critical wind speed under different conditions. e calculation results obtained in this paper are more accurate and reliable than those obtained by the previous method. e critical wind speed obtained in this paper can be applied to the antigalloping design of transmission lines under different conditions

Summary

Introduction

Self-excited vibration of iced transmission lines with low frequency and large amplitude occurs. According to what the authors know, squaring up the air wake effect, the galloping mechanical model of the iced quad bundle conductors with 3-DOF has not been studied. Based on the quasistatic theory, this paper establishes a galloping model of iced quad bundle conductors with 3-DOF, considers the influence of wake effect on the aerodynamic force of each subconductor, and theoretically deduces the stability judgment of transmission line system. Will generate horizontal velocity u_, and the torsional movement of the center of the bundled conductor will generate the horizontal velocity component rθ_ sin(α0i); the relative speed of the subconductor in the horizontal direction is U − u_ − rθ_ sin(α0i). (10c) where Cy, Cz, and Cθ are the whole aerodynamic coefficients of the quad bundled conductor in three directions, which can be obtained by the following formula: Cy 􏽘 Cyi Uri, αi􏼁, i 1.

Wind Tunnel Tests

Stability Calculation

Conclusion