Research on aeolian vibration of a conductor based on finite particle method. The study of aeroelasticity may be broadly classified into two fields. A substation is an installation that interconnects elements of an electric utilitys system. Pdf ultrahighvoltage transmission line is prone to severely aeolian vibration. Aeolian vibration is a low amplitude conductor diameter high frequency 5 to 150 hz phenomenon. Formation of the solar system documentary the inner secrets of planets and stars touch your heart 479 watching live now. Cfd numerical simulation of aeolian vibration of single. 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. Beginning vibration analysis with basic fundamentals by. The solutions listed in the preceding sections give us general guidelines for engineering a system to avoid or create. Aeolian vibration free download as powerpoint presentation. Study on aeolian antivibration of bundled conductor of.
Fluidstructure interaction fsi analysis was taken based on the coupling models, from which the property result of aeolian vibration numerical simulation was. Showcases secondstage, or aeolian, vibration in a steel or aluminum light pole. This piece disturbs the harmonic cycling of the shaft aeolian vibrations by touching the inside surface of the pole in a random and spiral manner. Harmonics stings on a stringed instrument such as a guitar or an aeolian harp can vibrate in a number of different ways. Index termstransmission lines, aeolian vibration, stockbridge dampers, laboratory test. To be valued as the premier operationsfocused trade association in the electric energy industry. Pdf study on aeolian vibration suppression schemes for large. Study on aeolian antivibration of bundled conductor of large. That vibration can, eventually, cause the wire to fatigue and break. Aeolian vibration is a type of motion caused by wind on conductors and overhead shield wires of transmission and distribution lines.
The spiral vibration damper is an impact type damper made of a rugged nonmetallic material that has a tight helix on one end that grips the. The aeolian vibration is a wellknown phenomenon affecting both single and bundle tl. Aeolian vibration dampers on power lines with images. Plps spiral vibration damper reduces aeolian vibration the high frequency, low amplitude vibration caused by horizontal wind passing across the line. Aeic encourages research and enables the exchange of technical information and best practices through a. The body is in equilibrium under the action of the two forces.
The frequency of aeolian vibration ranges from 3 to 50 hz and the wind speed ranges from 1 to 7 ms. Aeroelasticity problems can be prevented by adjusting the mass, stiffness or aerodynamics of structures which can be determined and verified through the use of calculations, ground vibration tests and flight flutter trials. This sustained vibration activity takes the form of discrete standing waves with forced nodes at the support structures and. Wenping xie 1, tian peng2, kai xiao, and jian zhang2.
Beginning vibration analysis with basic fundamentals. Transmission, sub transmission and distribution substation 4. From basic mechanics it is known that the bending strain in a beam. Sinusoidal vibration top and random vibration bottom 1.
The control of the aeolian vibration is deputed to the use of a suitable damping system. Here is the extension of the spring after suspension of the mass on the spring. A potential solution for longdistance power transmission leakage stray voltage from overhead lines causing a fluorescent lamp to glow electricity a complete. The ends of a power line span, where it is clamped to the transmission towers, are at most risk. Windinduced vibration and the effects on steel and aluminum. Wind induced aeolian vibrations of conductors and overhead shield wires. Aeroelasticity is the branch of physics and engineering that studies the interactions between the inertial, elastic, and aerodynamic forces that occur when an elastic body is exposed to a fluid flow. In order to research the problem of aeolian vibration occurred on single conductor in this paper, adina program was applied to set up the model of fluid domain and structure domain. Figure 2 vibration recorded on 38 ohsw 41 hertz sustained aeolian vibration activity occurs when the vortex frequency closely corresponds to one of the natural vibration frequencies of the span of conductor or ohsw. The phenomenon know as aeolian or second mode vibration is caused by lowvelocity, steady winds, normally ranging from 535mph and giving rise to frequencies of 220hz. Aeolian vibration causes damaging stress fatigue to the cable and represents the principal cause of failure of conductor strands.
International journal of engineering and technology, vol. The theory of the aeolian tone the theory of aerodynamic sound is based upon the wave equation for the fluid density p v2 i 02 p 4ax, 1 a2 tu oxj where tu p. Research advances of aeolian vibration of damperline system. Scribd is the worlds largest social reading and publishing site. Online monitoring analysis of aeolian vibration of. The amplitude of aeolian vibration less than diameter of the conductor. The frequency of aeolian vibration ranges from 3 to 50 hz and. Con tents preface xi chapter1 introduction 11 primary objective 1 12 elements of a vibratory system 2 examples of vibratory motions 5 14 simple harmonic motion 15 vectorial representation of harmonic motions 11 16 units 16 17 summary 19 problems 20 chapter 2 systems with one degree of freedomtheory 21 introduction 23 22 degrees of freedom 25 23 equation of motion. Third, two aeolian vibration schemes, the first one with vibration dampers only and the second one.
The damper is designed to dissipate the energy of oscillations in the main. Why are twisted pair cables used in electric power. Install a vibration dampener if aeolian vibration is suspected, it is recommended to take next steps to remedy the situation as quickly as possible. The simplest vibration is when the whole string vibrates up and down top but it is also possible to fit. 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. Electric substations with equipment used to convert highvoltage, extrahighvoltage ehv, or ultrahighvoltage uhv transmission lines to the intermediate voltage subtransmission lines or to switch subtransmission circuits operating at voltages in the range of 34. May 10, 2017 formation of the solar system documentary the inner secrets of planets and stars touch your heart 479 watching live now. Suppose that we need to stop a structure or component from vibrating e. Pdf aeolian vibrations on powerline conductors, evaluation of. Research on aeolian vibration of a conductor based on. Aeolian vibration known as windinduced vibration, has a high frequency and smallamplitude motion, which arises. Increased tension on bundled conductors appears to decrease their tendency to create induced oscillation and galloping. Im an electrical engineer, and understand how a twisted pair of wires can be used to reduce noise in the presence of magnetic fields. In the forcedconvection cooling mode, incoming wind can also induce the vibration of a transmission line 8, where aeolian vibration 9 10 11 is the most likely to occur and has the longest.
It shows that performances of dampers on the lines meet the standard of. Besides, the frequencies of lines are in accordance with frequencies in theory and. Old video i found on aeolian vibration fundamentals by preform products. Finally, we solve the most important vibration problems of all.
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. Overhead line aeolian vibration fibreoptic sensor bragg grating measurements. Mar 09, 2016 showcases secondstage, or aeolian, vibration in a steel or aluminum light pole. Relation of natural frequency to weight of supported body and stiffness of spring eq. The damper performance tests for the aeolian vibration of. Ohsw on transmission and distribution lines can produce damage that will. A potential solution for longdistance power transmission leakage stray voltage from overhead lines causing a fluorescent lamp to glow electricity a complete beginners guide covering watts, amps, volts, ohms and kwh. Pdf aeolian vibrations on powerline conductors, evaluation. Aeolian vibration is generally less pronounced on bundled conductors due to the effect of spacers andor spacer dampers installed at relatively close intervals along the line. However, i recently noticed the power company replacing the c. Aeolian vibration, which is the subject of this paper, is associated with smooth nonturbulent winds in the range of 2 mph to 15 mph, and can occur on a daily basis. As this steady stream of air passes across the pole, vortices are formed on the backside of the structure. Aeolian vibration fundamentals by preform products youtube.
The effect becomes more pronounced with increased cable tension, as its natural selfdamping is reduced. Principal modes 44 generalized and coupling 45 principal coordinates 158 46 modal analysis. The study results provided guidance to the design of aeolian anti vibration method. Aeolian vibration test for composite technologies corporation ref. Peters beginning vibration 2 introduction understanding the basics and fundamentals of vibration analysis are very important in forming a solid background to analyze problems on rotating machinery. Vecchiarelli 5 used the finite difference method to study response of aeolian vibration of the. Aeolian vibration known as windinduced vibration, has a high frequency and smallamplitude motion, which arises from alternating forces caused by vortex shedding. An iterative finitedifference scheme is derived to predict the vertical, steadystate, monofrequent, aeolian vibration of a single conductor span with a stockbridgetype damper attached. The association of edison illuminating companies aeic.
Aeolian vibration can be altered by as little as the shape of the structure, changing the fixture style or location, or having an object such as a tree or building alter the wind pattern. Vibration can be defined as simply the cyclic or oscillating motion of a machine or machine component from its position of rest. This numerical scheme is based on empirical models developed to represent the vortexinduced lift force from the wind as well as the forces of dissipation. Although any system can oscillate when it is forced to do so externally, the term vibration in mechanical engineering is often. It is common to refer to the transmission and distribution elements as networks or again, as systems. 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 vibration dampening system consists of a length of chain encased in a plastic tube that runs approximately twothirds the length of the pole. This vibration is believed to be predominantly caused by air vortexing around the structure. Aeic was founded by thomas edison and his associates in 1885 and is one of the most experienced associations in the electric energy industry. Vibration control is aimed at reducing or modifying the vibration level of a mechanical structure. Beginning vibration analysis connection technology center, inc.
In contrast to galloping and subconductor oscillations, aeolian vibration is characterized as high frequency, low amplitude motion. Windinduced vibration and the effects on steel and. At present, there is a lot of literature researching on aeolian vibration of a conductor at home and abroad. My task was to study aeolian vibration as it occurred, not in a harp, but in their power lines. The spiral vibration damper figure 10 has been used successfully for over 35 years to control aeolian vibration on these smaller sizes of conductors and wires. Aeolian vibration is characterised by low amplitude conductor diameter high frequency 5 to 150 hz. Switching between time and frequency is a common tool used for. It it designed to be used on opgw and conductors with an outside diameter less than 0. Early detection of this problem provides a greater solution base.
Though the extent of corona and radio noise is impacted by elevation air density, and other factors such as conductor surface condition and moisture, the bundle dimensions are the primary factor in mitigating the onset of the corona while increased aluminum content serves to reduce line losses and increase power flow, increased diameter also increases the conductors. Mechanism caused by smooth winds with velocity pdf when a smooth stream of air passes across a cylindrical shape, such as a conductor or ohsw, vortices eddies are formed on the leeward side back side. Wenping xie1, zuyan zhang 2, ningbo xu, li li 2, zheng wang, and xiaoyu luo1. Aeolian vibration often occurs in the highvoltage transmission overhead lines, and the amplitude of conductors has close relationship with conductors fretting wear. These elements can include generators, transmission lines, distribution lines, and even neighboring utility systems. Fluidstructure interaction fsi analysis was taken based on the coupling models, from which the property result of aeolian vibration numerical simulation was acquired. It is very difficult to measure actual amplitude of working conductor, so obtaining the amplitude of the conductor by the means of simulation is of practical significant to research quantitatively the relationship of the amplitude. Unit 7 vibration of mechanical vibration of mechanical. In a gentle wind, a power line will sing, just as a catgut or nylon string will sing in an aeolian harp. Without dampers, the amplitude of vi bration very much depends on conductor self damping, which may be very low. Combined with the theory of forced vibration analysis, lu 6 used impedance matrix transformation method to analyze the vibration response of conductor damper.
Online monitoring analysis of aeolian vibration of jiangmentongtangjia 220kv transmission line. Research on aeolian vibration of a conductor based on finite. Power balance approach, applicable to multimodal analysis. Aeolian vibrations occur almost on any transmission line, for low to moderate steady winds. If the amplitude of such vibration is sufficient, it can result in strand fatigue andor fatigue of conductor accessories. In engineering practice, we are almost invariably interested in predicting the response of a structure or mechanical system to external forcing.
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