УДК 62 –768 POWER LINES CONDUCTOR GALLOPING: TORSIONAL DAMPER AND DETUNER ON 400 KV LINES © G.A. Florea PhD, associate professor, Power & Lighting Tehnorob S.A., Bucharest, Romania E. Mateescu Fichtner Engineering S.A., Bucharest, Romania A.A. Vinogradov PhD, Senior Scientific Researcher, COMPOSITE ELECTRO LLC, Cheboksary, Russia N.A. Kiselyev Post-graduate student, Institute of State and Law of RAS, Moscow, Russia J.-L. Lilien DSc, academician, professor, Montefiore Institute of Liege University, Liиge, Belgium Abstract. <...> The torsional damper and detuner (TDD) as anti-galloping device for power lines was created and reported as early as 1993. <...> It is a mix of detuning properties, obtained by the classical pendulum, with dynamic action (the TDD device has its own eigenfrequency and damping). <...> This last playing a key role in the galloping phenomenon as observed on bundle conductor line: it avoids wind energy transfer from torsional movement to vertical movement. <...> Several versions were designed from the origin, tested and used in some projects, demonstrating their high capacity to solve the risk of the overhead line conductor galloping with usual frequencies in the range 0.2 –1 Hz. But until recently no large deployment occurred. <...> In 2013, collaboration between Russia, Romania and Belgium succeeded in manufacturing the device with up-to-date material to reach optimal characteristics. 130 devices were installed in 2013, live line, in Romania on a 400 kV line. <...> This paper will detail the new design and the remarkable TDD properties obtained. <...> I. INTRODUCTION The galloping [5, 6] is a phenomenon consisting of low frequency, high amplitude wind induced vibration of both single and bundle conductors, with a single or a few loops per span. Their frequencies are in the range of 0.1 to 1 Hz and their amplitudes vary from 0.1 to 1 times the actual sag of the conductor in the span. Usually, the galloping occurs in the conditions of moderately strong, steady wind acting upon an asymmetrically iced conductor surface. <...> The wind speed has to be higher than few m/s, but there is not an upper limit of the speed. <...> Galloping impact on the design of overhead lines consists of both clearances and loads on towers, because of conductor <...>