Study of new vibration suppression devices for application. This paper presented an overview on the dynamic analysis and control of the transmission towerline system in the past forty years. This is feasible for electric power transmission lines. Tuned mass dampers are used as stabilizers against harmonic vibration. Aeolian vibration is a risky problem of overhead transmission lines due to the conductor wire broken off sometimes for it. This vibration of transmission line in vertical plane can be categorized into two groups. Windinduced vibration of overhead conductors is common worldwide and can cause conductor fatigue near a hardware attachment. These two modes combined with the 19 strand messenger wire give afls stockbridge damper the widest range of vibration coverage in the industry. Design and testing of stockbridge vibration dampers 53, justice chandra madhav road, kolkata 700020. Vibration in transmission line is solved by using specially designed dampers. 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.
New york august 14, 2003 blackout in usa, initiated by increased conductor sag due to overheat. Dynamic responses and vibration control of the transmission. Stock bridge damper is most popular damper used for prevention of vibration in transmission line. Iec 61897, international standard, overhead lines requirements and tests for stockbridge type aeolian vibration dampers, first edition 199809. Transmission conductor dampers stockbridge type table 1 weight selection bare conductor diameter range weight see note 2 min max steel weight catalog number in mm in mm lb kg 1701 0. Vortx vibration damper vortx dampers respond to wind induced line vibration that is characterized by high frequency, low amplitude motion a. Windinduced vibration or aeolian vibration of transmission line conductors is a common phenomenon under smooth wind conditions. 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. Aeolian vibrations occur almost on any transmission line, for low to moderate steady winds. If you continue browsing the site, you agree to the use of cookies on this website. Tuned vibration absorbers can also be found in machinery of all sorts.
Vibration control of overhead transmission lines kasap, huseyin m. Noise and vibration transmission in complex structures 111 space and in frequency e. Inventoryaccessories dampers atlantis marine gear supply llc offers marine transmissions services and parts worldwide. 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.
If the physical background of the interaction between the vibration. Study of breeze vibration of overhead transmission lines. The dampers are so designed that they attenuate the line vibrations by reaching the same frequency as the cable that has wind. The intention of the specification is to guarantee satisfactory performance of the vibra tion dampers during the lifetime of the overhead line. Stockbridge damper vortx vibration damper preformed line. 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. Transmission torque converter arc spring damper dynamic. Effective damping is determined by more factors than just the use of vibration dampers. The present study provides a finite element formulation for an isoparametric cable element. Vibration dampers are used to absorb aolian vibrations of conductor of transmission lines, as well as ground wire, opgw, and adss. When the transmission line damper vibrates, the damper installed in the transmission line has the upper and lower vibration.
The finite element model of the building included levels 2, 3 and 4. Conductor is the important carrier of power transmission, and major constituent part of overhead transmission lines. It is analytically represented by weibull and rayleigh probability density functions with parameters estimated on the base of the experimental data. Abrasion is the wearing away of the surface of a conductor or ohsw and is generally. The problem is that, whilst distribution companies generally use smaller conductors than in transmission, the above statement is not true for all types of conductors. Study on aeolian antivibration of bundled conductor of. Vibration damper in transmission line electrical notes.
However, the damping ratio obtained by these dampers is very limited. Vibration dampers damping is the ability of a vibrating system or structure to dissipate energy. Balaji transmission products offering vibration damper, transmission line hardwares in kolkata, west bengal. The clamp grips the groundwire by means of an armor plate, which gives rise to the following issues regarding its operation. Galloping of iced power transmission lines with noncircular cross sections is in general characterized by low frequency 0. The vortx damper with large and small weights can achieve greater power dissipation and frequency response performance than symmetrical weight stockbridge damper designs. The vortex shedding action creates an alternating pressure imbalance, inducing the conductor to move up and down at right angles to the direction of airflow. Improving natural frequency of vibration in overhead transmission lines with concentrated masses. The challenges and future developing trends in the dynamic analysis and mitigation of the transmission towerline system under dynamic excitations are also put forward.
Vibration damper in transmission line vibration damper in. For example, most automobiles contain one or more tuned vibration absorbers. Design and testing of stockbridge vibration dampers. Dampers used in electrical transmission lines slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Transmission conductor vibration dampers stockbridge type1700 series damper to dissipate vibration, or wake up, at lower energy inputs. Each of these models used to conductwas static and transient dynamic analyses due to broken conductors in the middle span. 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. The movement of the wires occurs most commonly in the vertical plane, although horizontal or rotational motion is also possible. Damper location the span configuration value of safety coefficient used to reduce the reduce the.
A wide variety of transmission line fitting vibration dampers options are available to you, such as material. Dulhunty power, type test reports of 4d vibration dampers, march 2004. How does a small size damper reduce vibration in the. 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. About 3% of these are power distribution equipment, 77% are power accessories. Mar 20, 2011 vibration damper in transmission line. Pdf improving natural frequency of vibration in overhead. The damper is enclosed in an enclosure to prevent any ingress of water or dirt. Study of breeze vibration of overhead transmission lines with. To guarantee the suitability of the dampers a series of three tests has been compiled.
The vibration dampers function is to minimise the effect of windinduced vibrations. Apr 26, 2018 the overhead transmission line experiences vibrations in vertical plane. These are tuned vibration absorbers called stockbridge dampers that are installed to protect transmission lines from vibrations induced by wind. Vibration monitor locations established at distances of 8 to 200 feet from foundations. Ribe vibration dampers effective protection against conductor vibrations karman vortex street.
The problem of vibration control of overhead line conductors subjected to laminar transverse wind, which induces stationary vibrations by karman effect, is important due to the consequences on these structures lifetime and service. The vertical, steadystate breeze vibration of transmission line with dampers attached are studied using fem analysis. Normally, two dampers are required for each point of suspension of the conductors, one on either side and clamped to the conductor at appropriate distance depending upon the conductor size and density of material used for the conductor. Lines damaged by vibration may have to be derated or even taken out of service until repairs can be made. 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 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. Jun, 2014 dampers used in electrical transmission lines slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising.
A new type of damper and its field tests on icecoating. The parameters of fem emulation mode such as breeze vibration force, the conductor selfdamping and dampers damping are emphasized by the energy equivalent theory. Seminar grenoble 27 april 2006 cables vibrations due to wind action. 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. The vibrec damper recommendation program assists in damper requirements for transmission and distribution lines. Stockbridge damper vortx vibration damper preformed. Vibration minimisation by this method can only be considered for systems with a. The response of the conductor to vortex shedding excitation is strongly non linear in. One of the most common sources of transmission vibration lies with the exhaust system on your car. The number of dampers installed at one side of the span. The vibration damper is fixed in the transmission line through the clamp. The lines are simulated by cable element, the dampers by mass element and beam element. Very similar questions arise in the study of structural vibration within a simple system like a flat plate e. Helix offers solutions for supporting, protecting, terminating and splicing transmissions lines.
Ohsw on transmission and distribution lines can produce damage that will negatively impact the reliability or serviceability of these lines. Vibrations dampers are usually employed to handle aeolian, gallop and wakeinduced vibrations in the transmission lines. Sometimes, replacing your exhaust with one with different specifications than the original factory exhaust system can cause the normal operations the exhaust performs to pile up and send ripples of vibrations through the entire car, all the way to your transmission. Dampers with preformed clamps in general, fgtype dampers have been used on groundwires on ehv transmission lines, as shown in fig. Dampers data if the dampers are installed on the conductor the program needs. Tuned mass dampers tmds can be used as vibration control devices to improve the vibration performance of high. An efficient method for galloping profile monitoring of. 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.
To control flutter, transmission lines may be fitted with tuned mass dampers known as stockbridge dampers clamped to the wires close to the towers. Transmission conductor vibration dampers stockbridge type. Introduction we consider the cable model derived from the eulerbernoulli beam with viscous, hysteretic, or coulomb internal damping. Aug, 2017 vibrations dampers are usually employed to handle aeolian, gallop and wakeinduced vibrations in the transmission lines. The dynamic damper uses the inherent phase shift of resonance to provide a mass that will absorb energy from the vibrating system and thereby reduce amplitudes. Transmission lines are especially susceptible to vibrations as a result of their light weight. Theories of noise and vibration transmission in complex. 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. Vortx dampers respond to wind induced line vibration that is characterized by high frequency, low amplitude motion a. Apr 02, 2015 transmission lines are especially susceptible to vibrations as a result of their light weight. Sun sc, a model of transmission line vibration, phd thesis, the university of queensland, australia, 1999. Viscous dampers are one of the tools that can be applied to mitigate cable vibrations. Direct radio communications are established with the ground station gs.
Study of new vibration suppression devices for application to. A damper is a tuned mass device used to suppress windinduced vibrations on overhead power lines. Conductor gallop is the highamplitude, lowfrequency oscillation of overhead power lines due to wind. 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. Clutches, torque converters and dampers linking the engine and transmission in new drivetrain concepts dr. Request pdf vibration damper in transmission line vibration damper in transmission line windinduced vibration of overhead conductors is common worldwide and can cause conductor fatigue. The steel strand wire connected to the hammerhead bends up and down because of inertia of the hammerhead. The names of the files containing the mechanical impedance of the types of damper used. Vth samco workshop monitoring of overhead power transmission line user needs vienna, 2627 january, 2004 3 ulg montefiore institute of electricity 1. The transmission lines modeled with linear elastic truss and beam elements were used to perform the free vibration analysis to calculate the damping properties of the towers and the transmission lines. The frequency of vibration is of the order of 5 to 40 cyclesecond while. As the need for transmission of communication signals increase, many optical ground wiresopwg are replacing traditional ground wires.
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