Investigation into galloping characteristics of iced quad bundle conductors

Abstract

A nonlinear finite element method for galloping of iced bundle conductor transmission lines is presented. Wind tunnel tests for galloping of quad bundle conductor segments with crescent-shaped and sector-shaped ice models were carried out, and validity of the finite element method is demonstrated by the consistency of the galloping responses determined by the numerical method and those measured by the wind tunnel tests. Numerical models of four sections of iced transmission lines with different Irvine parameter l 2 , which determines if internal resonance exists, are set up. Galloping of the iced transmission lines in steady wind flow and stochastic wind field is numerically simulated by the presented finite element method. Based on the numerical results, galloping characteristics of the iced transmission lines with and without internal resonance in steady and stochastic wind fields are discussed. It is found that the galloping mode and frequency of an iced quad bundle conductor transmission line in a stochastic wind field are similar to those in a steady wind flow, but the galloping amplitude may be different. Moreover, the Irvine parameter l 2 may be used to estimate some galloping characteristics, such as galloping mode and coupling movement induced by internal resonance.

Wind Tunnel Test Investigation on Unsteady Aerodynamic Coefficients of Iced 4‐Bundle Conductors

“…ese formed ice shapes may lead to conductor motion. Combined with actual observation, crescent-shape and sector-shape can be generalized with respect to the great variety of natural heavy ice shape [16,20]. e aerodynamic forces of bundle conductors are the foundations of analysis of the conductor motion of transmission lines [5].…”

“…Compared with the aerodynamic coe cients of single conductor, owing to the wake ow induced by the windward subconductors, the aerodynamic coe cients of the subconductors located in leeward side are signi cantly di erent with each other. e de nition about the drag, lift, and torsional moment coe cients of the iced subconductor is shown in the references [16,20,23]. In the test, the aerodynamic loads exerted on each subconductor are measured by balance; the unsteady drag coe cient C D , lift coe cient C L , and moment coe cient C M of each subconductor can be calculated with equation (1), where ρ is the density of the air at room temperature, L is the length of the conductor, and U is the wind velocity.…”

“…Yan et al [19] used wind tunnel test to measure the aerodynamic coefficients of 4-bundle conductors; the aerodynamic coefficients of each subconductor varying with wind attack angles were obtained. Yan et al [20] proposed the numerical method to investigate galloping behaviors of iced 4-bundle conductor lines based on the results of crescent-shape iced 4-bundle conductors obtained by the wind tunnel test. Wind tunnel tests were carried out by Li et al [21] to obtain the steady aerodynamic characteristics of crescent-shape iced 4-bundle conductors which are used in 500 kV UHV transmission lines with different test conditions (ice thicknesses, initial ice accretion angles, bundle spaces, and wind attack angles).…”

Mitigation of conductor line galloping by a direct cable-connection to non-conductive composite power pylons

“…lines, depending on the type of conductor line and ice accretion [39][40][41][42]. An average damping ratio of = 3.2 % was employed, applicable to Abaqus using the Rayleigh model.…”

Galloping Reduction of Transmission Lines by Using Phononic Crystal

“…Therefore, the mechanisms, as well as the precautions, of galloping have provoked much attention. From carrying on wind tunnel tests [3,4], prototype tests [5,6], and simulation computation [7,8], remarkable achievements have been made. For now, it is generally believed that galloping is a self-excited vibration because of the aerodynamic instability when conductors accrete ice [9].…”