Hysteresis Phenomenon in the Galloping of the D-Shape Iced Conductor

Abstract

It is well known that there is a hysteresis phenomenon in the amplitude variation in the iced conductor galloping with the wind velocity, which will have more obvious disadvantages to the overhead transmission lines. But hysteresis characteristics in the conductor galloping have not received much attention. In this paper, a continuum model of the conductor galloping with D-shape ice is derived by using Hamilton principle, where the initial deformation, the geometric nonlinearity caused by the large deformation, and the aerodynamic nonlinearity are considered. The aerodynamic forces are described by using the quasi steady hypothesis, where the aerodynamic coefficients are expanded by the polynomial curves with a third order and a ninth order, respectively. The hysteresis phenomenon is analyzed by using the approximate solutions of the Galerkin discretized equation derived from the continuum model by means of the harmonic balance method. The influence of the different factors, dynamic angle of attack, span length, initial tension, and conductor mass, is obtained in different galloping instability intervals. And two important aspects about the point of the hysteresis phenomenon onset and the size of the hysteresis region over the wind velocities are analyzed under different conditions.

Analysis of wind attack angle increments in wind tunnel tests for the aerodynamic coefficients of iced hangers

“…Test model Variable range of wind angle attack (°) Wind attack angle increment (°) Li et al (2016) Iced cables 0 to 180 2 Fleming and Popplewell (2010) Lightly iced conductors 0 to 360 2 Chabart and Lilien (1998) Iced conductors -180 to 180 5 Lou et al (2014) Iced conductors 0 to 180 5 Cai et al (2015) Iced conductors 0 to 180 5 Yan et al 2014Iced conductors 0 to 180 5 Keutgen and Lilien (2000) Iced conductors 2180 to 180 5 Gjelstrup et al (2012) Iced bridge hangers 290 to 90 5 Yan et al 2013Iced conductors 2180 to 180 5 Liu et al (2013) Iced conductors 2180 to 180 5 Ma et al 2017Iced conductors 0 to 90 10 Chadha and Jaster (1975) Iced conductors 0 to 360 10 Demartino 2014Iced bridge hangers 0 to 180 10 Nigol and Buchan (1981) Iced conductors 280 to 80 20 2017Iced conductors 0 to 90 10 2 Chadha and Jaster (1975) Iced conductors 0 to 360 10 5 Nigol and Buchan (1981) Iced conductors 280 to 80 20 18…”

“…However, previous studies have not defined the specific wind attack angle increments, and different scholars have adopted nonidentical values. As shown in Table 1, different wind attack angle increments, such as 2° (Fleming and Popplewell, 2010; Li et al, 2016), 5° (Cai et al, 2015; Chabart and Lilien, 1998; Gjelstrup et al, 2012; Keutgen and Lilien, 2000; Liu et al, 2013; Lou et al, 2014; Yan et al, 2013, 2014), 10° (Chadha and Jaster, 1975; Demartino, 2014; Ma et al, 2017), and 20° (Nigol and Buchan, 1981), have been adopted in existing research while performing wind tunnel tests for the aerodynamic coefficients of iced cable structures. Therefore, selecting appropriate wind attack angle increments that can ensure the accuracy of the test data, shorten the period of experiment, and reduce the expense of the experiment is a problem that should be addressed immediately.…”

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

“…The schematic cross section of a conductor line with a D-shaped ice accretion, frequently used in numerical galloping studies [33,34], is represented in Fig. 5.…”

Free vibration analysis of transmission lines based on the dynamic stiffness method

“…A number of investigations on internal resonances of galloping have been published [34–37]; however, these methods have been restricted to single span with fixed ends. In addition, Zhou et al .…”