Numerical Simulation Study On Anti-galloping Of Six Bundle Conductors In Test Transmission Line

The galloping of an electrical transmission line is characterized by large amplitude,low frequency, self-excited oscillation, which is occurred under action of continuouswind forces. Overhead lines galloping may bring some huge damages such as rupture ofconductor and hardware fittings, failure of tower bolt or even collapse of the tower andit is threatening seriously for safe operation of electrical transmission line. Therefore,the studies on the galloping characteristic and anti-galloping of iced bundle conductorbehave great significance on theoretical and engineering practice.Galloping of six bundle conductors of the test transmission lineaccreted ices with atypical cross-section shape of ’’D" under the tested wind is simulated by means of thefinite element software ABAQUS，and the results are compared with those observed inthe field test. The efficiency of the numerical model is demonstrated that the amplitude,mode and tension of the conductor galloing simulated is closed to those observed in thefield test. Galloping of six bundle conductors accreted ices with a typical cross-sectionshape of crescents under different winds speeds is also simulated. It is observed that thegalloping mode is focused on two half-wave and the critical wind speed of galloping ofsix bundle conductors accreted ices with a typical cross-section shape of crescents islarger than that of six bundle conductors accreted ices with a typical cross-section shapeof ’’D". The galloping mode may change and tend to be forcused on low-order madalwhen the wind speed increases to a certain degree.The numerical modeling of double pendulum dampers is realised and the dynamicresponse of the transmission line with double pendulum dampers is simulated. It isshown that little anti-galloping efficiency is obtained after installation of the doublependulum dampers, which is consistent with the observed result from the fieldtest.Parameters such as the quality of swing arms, the quality of pendulums, the lengthof swing arms, tilt angle of swing arms and installation positions of double pendulumdampers are inverstigated accoding to the galloping characteristics. The results indicatethat the increase of qualities of swing arms and pendulums and the length of swing armscan improve the anti-galloing effect. But changes of the tilt angle of swing arms haslittle anti-galloping effect. The optimization of installation positions increases theanti-galloing effect from11.26%to23.25%. The schemes which have someanti-galloping effect are combinated to find the optimal solution. The result shows that the scheme of the combiantion of the length of swing arms and installation positions isthe optimal solution which has the anti-galloping effect by34.02%.The anti-galloping effect of a new anti-galloping device is inverstigated. The resultshows that it has better anti-galloping effect than double pendulum dampers. Based onthe galloping characteristics the installation position of the new anti-galloping device isoptimized.