Transmission conductor vibration dampers stockbridge type. Most overhead lines damped with stockbridge dampers have satisfactory performance. Stockbridge vibration dampers comprise of a pair of weights joined by a stranded. Vibrec damper recommendation program the vibrec damper recommendation program assists in damper requirements for transmission and distribution lines. Vibrations dampers are usually employed to handle aeolian, gallop and wakeinduced vibrations in the transmission lines.
In recent years, aaac conductor has been a popular choice for transmission lines due to its high electrical carrying capacity and high mechanical tension to mass ratio. The invention provides a stockbridge vibration damper comprising a pair of damping weights joined by a stranded steel cable, a clamp attached to the cable at a location intermediate the weights for attachment to an overhead power transmission line. 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. As the need for transmission of communication signals increase, many optical ground wiresopwg are replacing traditional ground wires. Mar 20, 2011 vibration dampers are widely used to control aeolian vibration of the conductors and earth wires including optical ground wires opgw. Aeolian vibrations occur almost on any transmission line, for low to moderate steady winds. Comparative testing was conducted in 1993 at a private test site using afl stockbridge dampers and those of two competitors. The vibrec damper recommendation program assists in damper requirements for transmission and distribution lines. Vibration control of overhead transmission lines kasap, huseyin m. Vibration dampers are used to absorb aolian vibrations of conductor of transmission.
Online monitoring analysis of aeolian vibration of jiangmen. Simplified vibration model and analysis of a singleconductor transmission line with dampers o barry, r long, and dcd oguamanam proceedings of the institution of mechanical engineers, part c. Feb 22, 1972 a vibration damper and transmission line comprising. A damper is basically a device which is so designed to absorbed vibration energy and prevent vibration in. Vibration damper in transmission line vibration damper in. Aeolian vibration is one of the most important problems in transmission lines because it represents the major cause of fatigue failure of conductor strands or of items associated with the support, use, and protection of the conductor. To reduce the vibration of a primary device by adding an absorber to the system applications. Keywords aeolian vibration, transmission line vibration, overhead conductors, vibration dampers 3.
There are thus normally two dampers per span, though more can be installed if necessary on longer spans. And iee standard is a good way to verity the damper performance. Stockbridge dampers in the shape of dumbbell with midpoint clamped to the line are used for damping the aeolian vibration. Overhead transmission lines vibrationdampers svenska kraftnat. The lines are simulated by cable element, the dampers by mass element and beam. Final feasibility update report casa update f2 02094srp030001 f. Documents for the proposal the bidder will submit together.
In any conductor the dampers are used at both the ends of the span. Overhead transmission lines form a catenary for which vibration is predominately in the vertical plane. But transmission line and damper system cannot completely protect the lines from the destruction of aeolian vibration. Pdf study of new dampers for application to overhead. When working in the area of energized lines with this. The dampers are so designed that they attenuate the line. Study of breeze vibration of overhead transmission lines with. Us6943290b2 vibration damper for overhead power lines. Ribe vibration dampers remove the wind energy from the conductor and reduce vibration stresses sufficiently to ensure a long life for the overhead transmission lines. Dampers used in electrical transmission lines slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising.
Aeolian vibration of overhead groundwires is intense in transmission lines located. Mm powerline transmission offering mmpt iron vibration damper at rs 310piece in howrah, west bengal. Jiangmentongtangjia 220kv transmission line which distance from the coastline in the range of 5km. Dampers are also used as supplemental protection at deadends. The conductor galloping is a selfexcited vibration caused by wind excitation to iced transmission line conductors which leads to strand break and wire break due to conductor fatigue and. Experiments are performed to determine the equivalent viscous damping of the damper. Aeolian vibration is a low amplitude conductor diameter high frequency 5 to 150 hz phenomenon. Study of new vibration suppression devices for application to ehv. Windinduced vibration of overhead conductors is common worldwide and can cause conductor fatigue near a hardware attachment. Aeolian vibration is a low amplitude conductor diameter high frequency 5 to 150. Study on aeolian vibration of overhead conductors with dampers. The damper performance tests for the aeolian vibration of. About 3% of these are power distribution equipment, 77% are power accessories.
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. Helical rods are wrapped around the cable and suspender to hold the suspender in place. If you continue browsing the site, you agree to the use of cookies on this website. Request pdf on aug 31, 2018, sooman park and others published vibration characteristics of stockbridge damper for transmission line find, read and cite all the research you need on researchgate. Aug, 2017 vibrations dampers are usually employed to handle aeolian, gallop and wakeinduced vibrations in the transmission lines. Documents for the proposal the bidder will submit together with his offer the following documents from the manufacturer. The invention provides a stockbridge vibration damper comprising a pair of. Afl vibration dampers may be installed without disassembly of the clamp parts. Apr 26, 2018 vibration in transmission line is solved by using specially designed dampers. Spiral vibration dampers are also effective on certain size overhead. When more than one plane of vibration is anticipated, stockbridge dampers may be mounted at right angles to each other. 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.
Construction maintenance and repair liveline barehand. A damper is basically a device which is so designed to absorbed vibration energy and prevent vibration in transmission line. As shown in the figure they are fitted at a position most effective in damping the vibration. Us3644660a overhead transmission line and attached. Energy balance method ebm is another method used to examine the forced vibration analysis of transmission lines. 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. 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. Apr 19, 2019 apr 19, 2019 wazipoint is an engineering blog. On the vibration analysis of power lines with moving dampers ma bukhari1, o barry1 and e tanbour2 abstract this work investigates the performance of a moving damper for overhead transmission lines. The requirements of transmission lines tend to be higher and softer which make the diameter of wire diameter and span larger, transmission line suspension points. As shown in the figure they are fitted at a position most effective in damping the. Aeolian vibration, transmission line vibration, overhead conductors, vibration dampers. Aeolian vibration is one of the most important problems in transmission lines because it represents.
Stockbridge vibration dampers comprise of a pair of weights joined by a stranded steel cable commonly known as a messenger cable and a clamp attached to the cable at a location intermediate the weights for attachment to an overhead. Aeolian vibrations are usually caused by winds ranging in velocity from1to7ms and can occur at frequencies from3to150hz with peaktopeak displacement amplitudes of up to one conductor diameter. Vibration dampers are used to absorb aolian vibrations of conductor of transmission lines. A vibration damper and transmission line comprising. Karman vortex street ribe vibration dampers effective protection against conductor vibrations. Control of vibration of transmission lines article pdf available in international journal of acoustics and vibrations 152. Vibration in transmission line is solved by using specially designed dampers. Stock bridge damper is most popular damper used for prevention of vibration in transmission line. Dampers are used both in the phase and ground conductors. Simplified vibration model and analysis of a singleconductor transmission line with dampers o barry1, r long1 and dcd oguamanam2 abstract a novel model is developed for a vibrating singleconductor transmission line carrying stockbridge dampers. This provides maximum effectiveness in controlling the levels of subconductor motions. Vibration damper in transmission line electrical notes. 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. Valid iso 9001 certificate, as defined in the threshold conditions.
Journal of sotmd and vibration 1978 60 2, 217237 transmission line vibrations m. The authors emphasize the importance of choosing appropriate design tension, type, quantity and placement of vibration dampers. Pdf aeolian vibration of overhead groundwires is intense in transmission lines located in flat and windy areas. Dec 10, 2017 vibration dampers are widely used to control aeolian vibration of the conductors and earth wires including optical ground wires opgw. The damper of claim 1 in which said helical rod extends along the line and both sides of said suspender. Aeolian vibrations are usually caused by winds ranging in. The purpose of the guideline is to guarantee satisfactory performance of the vibration dampers during the lifetime of the overhead transmission. Conference paper pdf available october 1998 with 728 reads. Lines damaged by vibration may have to be derated or even. Reciprocating machines building excited by an earthquake. Vibration dampers are used to absorb aolian vibrations of conductor of transmission lines, as well as ground wire, opgw, and adss.
They are characterised by small amplitudes of vibration one conductor diameter with frequency between 5. A wide variety of transmission line fitting vibration dampers options are available to you, such as material. Vibration characteristics of stockbridge damper for. Modern spacer dampers are characterized by an accurate coordination between the inertial and elastic damping properties. The vertical, steadystate breeze vibration of transmission line with dampers attached are studied using fem analysis. How does a small size damper reduce vibration in the. Ohsw on transmission and distribution lines can produce damage that will negatively impact the reliability or serviceability of these lines. Mmpt iron vibration damper, rs 310 piece mm powerline. Aeolian vibration of overhead electrical transmission lines, also referred to as conductors, are very common and can lead to fatigue damage. The vibration level is evaluated by determining the balance between the. Energy balance method ebm is another method used to examine the forcedvibration analysis of transmission lines.
Jun, 2014 dampers used in electrical transmission lines slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. The vibration level is evaluated by determining the balance between the energy imparted to the conductor by the wind and the energy dissipated by the conductor via conductor selfdamping and the added dampers. 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. Rao department of applied liechanics, indian institute of. For high voltage transmission lines, conductor bundles. This product is intended for use by trained craftspeople only. This paper is a resume of available data concerning the causes of and remedies for wire failure in overhead line conductors subject to the eddy vibration due to steady winds ranging from 5 to 25. Overhead transmission lines form a catenary for which vibration is predominately in the vertical. Journal of vibration and control on the vibration analysis of. The dampers are so designed that they attenuate the line vibrations by reaching the same frequency as the cable that has wind.
This new transmission concept shows how enjoyment, consumpti on and comfort can be combined with impressive results. Vibration dampers are widely used to control aeolian vibration of the conductors and earth wires including optical ground wires opgw. 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. Construction maintenance and repair liveline barehand annotated instructors guide module overview this module introduces trainees to tasks in the power transmission environment that are. In recent years, aaac conductor has been a popular.
The degree of protection needed on a specific line depends upon a number of factors such as line design, temperature, tension, exposure to wind flow, and vibration history on similar construction in the same area. Construction maintenance and repair liveline barehand annotated instructors guide module overview this module introduces trainees to tasks in the power transmission environment that are often conducted while lines and components are live, performed with intentional contact between the worker and the energy source. Simplified vibration model and analysis of a singleconductor. A vibration damper for an overhead cable having a cshaped cushioned elastomer lined suspender engaging the cable and a vibration damper suspended below it. Lines damaged by vibration may have to be derated or even taken out of service until repairs can be made. The lines are simulated by cable element, the dampers by mass element and beam element. In recent years, aaac conductor has been a popular choice for transmission lines due to its high electrical carrying capacity and high mechanical. A stockbridge vibration damper is a seismic device used for damping overhead power transmission lines. Vibration and vibration dampers in transmission line. Technical guideline for vibration dampers with preformed helical rods for overhead earth wire, see tr 05092e. The damper is designed to dissipate the energy of oscillations in the main cable to an acceptable level. Stockbridge dampers installed on high voltage power lines. Research advances of aeolian vibration of damperline system. Sep, 2005 a stockbridge vibration damper is a seismic device used for damping overhead power transmission lines.
Vibration minimisation by this method can only be considered for systems with a single frequency of excitation. 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. The data got from the monitoring of a6 and a7 tower to analysis the aeolian vibration situation, and. Vibration damper in transmission line divyas blog for. Stockbridge dampers are devices extensively used to reduce vibration amplitude on electric. Simplified vibration model and analysis of a singleconductor transmission line with dampers o barry1, r long1 and dcd oguamanam2 abstract a novel model is developed for a vibrating singleconductor. This invention relates to the design and manufacture of stockbridge type vibration dampers for overhead power transmission lines.
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