What is aeolian vibration?
What is aeolian vibration?
Aeolian vibration, which is the subject of this paper, is associated with smooth (non-turbulent) winds in the range of 2 MPH to 15 MPH, and can occur on a daily basis. In contrast to galloping and sub-conductor oscillations, aeolian vibration is characterized as high frequency, low amplitude motion.
What are the source of vibration in a transmission line?
The cause of vibration is that the vortexes shed alternatively from the top and bottom of the conductor at the leeward side of the conductor. 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.
What is vibration damper in power system?
Vibration dampers are widely used to control Aeolian vibration of the conductors and earth wires including Optical Ground Wires (OPGW). • 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.
What are different types of transmission lines?
Types of transmission line include parallel line (ladder line, twisted pair), coaxial cable, and planar transmission lines such as stripline and microstrip. The higher the frequency of electromagnetic waves moving through a given cable or medium, the shorter the wavelength of the waves.
What causes Aeolian vibration?
Aeolian vibration is a type of motion caused by wind on conductors and overhead shield wires of transmission and distribution lines.
What are aeolian vibrations in overhead transmission line conductors Mcq?
What are aeoline vibrations in overhead transmission line conductors? Explanation: Aeoline vibrations are high frequency (as high as 500 Hz) and low amplitude (20 mm to 50 mm ) vibrations. They are caused by vortex phenomenon in light winds (5 to 20 Km/hr).
What is sag and tension?
Tension -The sag is inversely proportional to the tension in the conductor. Higher tension increases the stress in the insulators and supporting structures. Wind – It increases sag in the inclined direction. Temperature – The sag is reduced at low temperatures and is increases at higher temperatures.
What is damper and its types?
Seismic dampers permit the structure to resist severe input energy and reduce harmful deflections, forces and accelerations to structures and occupants. There are several types of seismic dampers namely viscous damper, friction damper, yielding damper, magnetic damper, and tuned mass damper.
What VSWR means?
Voltage Standing Wave Ratio
VSWR (Voltage Standing Wave Ratio), is a measure of how efficiently radio-frequency power is transmitted from a power source, through a transmission line, into a load (for example, from a power amplifier through a transmission line, to an antenna). In an ideal system, 100% of the energy is transmitted.
What voltage is transmission?
Transmission Line Transmission lines carry high voltage electricity, typically at 345,000 volts, over long distances between the power generation plant and customers. In some cases, a large industrial customer may receive electricity directly from overhead transmission lines.
What are aeolian vibration in transmission lines?
Aeolian vibration is a type of motion caused by wind on conductors and overhead shield wires of transmission and distribution lines. Aeolian vibration is characterised by low amplitude (conductor diameter) high frequency (5 to 150 Hz).
What are the methods used to protect conductors against high frequency aeolian vibrations?
Explanation: The conductors are protected by dampers. Dampers prevents the resonant vibrations from reaching the conductors at the clamps or supports.