A damper is a tuned mass device used to suppress windinduced vibrations on overhead power lines. To maintain this quality, the dampers should be protected, preferably in their shipping containers, from dirt and foreign material prior to installation. Keywords aeolian vibration, transmission line vibration, overhead conductors, vibration dampers 3. The amplitude at which a span will vibrate peaktopeak movement at the antinode in figure 3 depends on a number of factors which include the energy that is transferred to the span by the wind and the amount of damping in the span from the conductor or ohsw itself self damping or from additional dampers installed in. Balaji transmission products offering vibration damper, transmission line hardwares in kolkata, west bengal. Aeolian vibration, transmission line vibration, overhead conductors, vibration dampers. At the free running speed of motion the moment mg is equal to the moment of the resistance motionmc, and the first mass is effected by the distributing component of the moment of engine device. Afl vibration dampers are produced with carefully designed and controlled surface finishes for high voltage use. Rienstra department of mathematics and computing science, eindhoven university of technology, the netherlands s. Glyn havard and others published vibration dampers, by david g.
The smart grid demands the transmission towers failure malfunction probability comes down to a minimum level. Pdf study of new dampers for application to overhead. The purpose of the guideline is to guarantee satisfactory performance of the vibration dampers during the lifetime of the overhead transmission line and shall be used for the purchase of vibra tion dampers. This proposed model excellently captures free vibration characteristics of the system. Viscous dampers are one of the tools that can be applied to mitigate cable vibrations. Vibration damper in transmission line electrical notes. Real time monitoring of high voltage transmission line. Potential of viscous dampers for vibration mitigation of. However, the damping ratio obtained by these dampers is very limited.
Design and testing of stockbridge vibration dampers. The electric current flowing in the lines should be measured to avoid overloads, phase unbalance and fluctuation. They are characterised by small amplitudes of vibration one conductor diameter with frequency between 5 and 100 hz, depending on the conductor size and tensile load. Pdf the problem of vibration control of overhead line conductors subjected to laminar transverse. Study on aeolian antivibration of bundled conductor of large. Conductor is the important carrier of power transmission, and major constituent part of overhead transmission lines. Ozgen september 2012, 92 pages this thesis aims to examine the performance of stockbridge dampers used to suppress aeolian vibrations on overhead transmission lines arising from the wind. Vibration dampers are used to absorb aolian vibrations of conductor of transmission lines, as well as ground wire, opgw, and adss. The dumbbellshaped device consists of two masses at the ends of a short length of cable or flexible rod, which is clamped at its middle to the main cable.
Mar 20, 2011 vibration damper in transmission line. Simplified vibration model and analysis of a singleconductor. Pdf aeolian vibration of overhead groundwires is intense in transmission lines located. Conductor gallop is the highamplitude, lowfrequency oscillation of overhead power lines due to wind.
How does a small size damper reduce vibration in the. The free vibration of a transmission line conductor equipped with a number of stockbridge dampers is modelled by a differential equation of motion of a tensioned beam acted on by concentrated frequency dependent forces, and an exact solution is obtained using integral transformation. The dampers are so designed that they attenuate the line vibrations by reaching the same frequency as the cable that has wind. Health monitoring of overhead power transmission line.
It is shown that the natural vibration is the gravity mode, of which the tension component vanishes in the first harmonic. The problem originates from a study of the phenomenon of galloping, which is a highamplitude periodic oscillation of overhead transmission lines. Article information, pdf download for simplified vibration model and. Apr 26, 2018 while aeoline vibration is itself not harmful but it may give rise to troubles at points where free vibration is restricted. In the neutral position, the input shaft 1 drives the counter shaft 2 which spins freely. Let us explain the concept of tuned mass dampers in brief. Transmission of impact vibration on concrete and mortar sheets. Figure 10 shows the four shift positionsof the manual transmission shown in figure 9. Jan 19, 2006 the weakly nonlinear, freely vibrating motion of a system of coupled spans of suspended overhead transmission lines is studied. Nonlinear free vibrations of coupled spans of overhead transmission lines sjoerd w.
The authors emphasize the importance of choosing appropriate design tension, type, quantity and placement of vibration dampers to avoid failure of lines. Apr 02, 2015 transmission lines are especially susceptible to vibrations as a result of their light weight. A wide variety of transmission line fitting vibration dampers options are available to you, such as material. Helix offers solutions for supporting, protecting, terminating and splicing transmissions lines. Vibration dampers damping is the ability of a vibrating system or structure to dissipate energy. The second schematic shows the transmission in first gear.
World climatic changes have an impact on our existing electrical transmission line performance. The dampers have been applied to 750kv transmission lines, and they offer easy installation. Energy dissipated by the transmission line conductor formula 3. Vortx vibration damper vortx dampers respond to wind induced line vibration that is characterized by high frequency, low amplitude motion a. Transmission conductor vibration dampers stockbridge type1700 series damper to dissipate vibration, or wake up, at lower energy inputs. Single conductor dampers stockbridge dampers multiple conductor dampers spacer dampers a stockbridge damper is the most commonly used type of damper worldwide. A stockbridge damper is a tuned mass damper used to suppress windinduced vibrations on slender structures such as overhead power lines and long cantilevered signs. Direct radio communications are established with the ground station gs.
Pdf transmission of impact vibration on concrete and mortar. The present study provides a finite element formulation for an isoparametric cable element. Vibration control of overhead transmission lines kasap, huseyin m. The parts of the fourth floor where vibration complaints reported response locations and the locations of various gym equipment and class activities excitation locations were studied together to determine possible vertical vibration transmission scenarios. Aug, 2017 vibrations dampers are usually employed to handle aeolian, gallop and wakeinduced vibrations in the transmission lines. Stockbridge damper vortx vibration damper preformed line.
Ohsw on transmission and distribution lines can produce damage that will. Pdf download for on the vibration analysis of power lines with. Vibration dampers material damping structural damping. A damper is basically a device which is so designed to absorbed vibration energy and prevent vibration in transmission line. Vibration in transmission line is solved by using specially designed dampers. Index termstransmission lines, aeolian vibration, stockbridge. Jun, 2014 dampers used in electrical transmission lines slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Journal of sotmd and vibration 1978 60 2, 217237 transmission line vibrations m. This paper presented an overview on the dynamic analysis and control of the transmission towerline system in the past forty years. The finite element model of the building included levels 2, 3 and 4.
Tuned vibration absorbers can also be found in machinery of all sorts. These two modes combined with the 19 strand messenger wire give afls stockbridge damper the widest range of vibration coverage in the industry. If you continue browsing the site, you agree to the use of cookies on this website. In addition, dampers, conditions for damping, free and forced vibrations of the overhead conductor were considered in the fem model. This system is able to detect variations in transmission of vibration at the same frequency between the. Pdf control of vibration of transmission lines researchgate. Contribution to the cea workshop on transmission line asset maintenance. The top schematic in figure 10 has the transmission in the neutral position which is what is seen in figure 9. Weights made up of cast iron, clamp made up of aluminum alloy, nuts and bolts made up of galvanized or stainless steel and messenger cable made up of galvanized steel.
Aeolian vibrations occur almost on any transmission line, for low to moderate steady winds. Mostly mechanical energy is converted to heat energy when the dissipation is by internal friction or hysterisis characteristics due to its molecular structure material damping. The movement of the wires occurs most commonly in the vertical plane, although horizontal or rotational motion is also possible. Aeolian vibration is a risky problem of overhead transmission lines due to the conductor wire broken off sometimes for it. Vibration and vibration dampers in transmission line.
About 3% of these are power distribution equipment, 77% are power accessories. Figure5a shows a graph of load changes in the elastic link transmission without damping, as figure5b. The vortx damper with large and small weights can achieve greater power dissipation and frequency response performance than symmetrical weight stockbridge damper designs. Handling in the field should be with care to avoid mechanical damage. Its function is to balance the vibration of a system with another comparatively lightweight component so as reduce the impact of the worstcase vibrations on the system. Download fulltext pdf whole body vibration energy transmission in a passive and electromechanically active suspension seat conference paper pdf available september 2012 with 59 reads. Damper characterization test, tuned vibration absorbers. Dynamic responses and vibration control of the transmission. Nonlinear free vibrations of coupled spans of overhead.
For example, most automobiles contain one or more tuned vibration absorbers. Transmission tower vibration analysis system based on. On the vibration analysis of power lines with moving dampers ma. These are tuned vibration absorbers called stockbridge dampers that are installed to protect transmission lines from vibrations induced by wind. Windinduced vibration of overhead conductors is common worldwide and can cause conductor fatigue near a hardware attachment as the need for transmission of communication signals increase, many optical ground wiresopwg are replacing traditional ground wires. The analytical expression of the kinetic energy of the cable is compared with the amount of dissipated energy, obtained by experimental means, for the control of vibration of transmission lines. Pdf transmission of impact vibration on concrete and. This program allows users to perform analysis on transmission lines by inputting various mechanical and. Further to our complete helical fitting line, we offer a full array of innovative motion control products designed to withstand severe weather conditions, as well as a wide range of conductor accessories built to be easy to install and reliable. Tuned mass dampers are used as stabilizers against harmonic vibration. Rao department of applied liechanics, indian institute of technology, madras 600036, lndia received 31 august 1977, and hi revised form 23 march 1978 various forms of dampers are used to suppress vibrations in transmission lines. The damper performance tests for the aeolian vibration of.