How does a Stockbridge damper work?
So how do Stockbridge dampers actually work? In simple terms, Kranz says, the vibration in the structure is dampened “through the shaking of the two weights on either end of the damper.”
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.
Why damper is used in transmission line?
The damper is designed to dissipate the energy of oscillations in the main cable to an acceptable level. Its distinctive shape gives it the nickname “dog-bone damper“. These dampers are used to counteract vibrations excited by wind, so-called Karman vibrations.
Why We Use spacers in transmission line?
The key function of a phase spacer is to prevent the approach of phase conductors on a high voltage overhead circuit due to formation of ice sleeves and the presence of strong wind. Such natural events can lead to deflection of conductors that are subjected to the increased mechanical loads being generated.
Why are there weights hanging on power lines?
The white blobs are the weights. Here is a closeup of a single weight: They appear to be just concrete blocks with no dashpot or any other apparent way to dissipate power. These weights seem to be at 1/4 and 3/4 of each span, which would be the nodes of the first harmonic standing wave.
Why are there weights on power lines?
The weights are mounted on flexible arms, typically a length of stiff cable, which allow the assembly to absorb energy that might otherwise be imparted to the longer power lines, or more accurately, that kinetic energy (movement) is removed from the lines, preventing oscillation.
What is good vibration damping?
Sorbothane is a great solution for vibration damping Normally engineers try to address and reduce this energy at its source so the disturbing force is not at or near a natural frequency. This will ensure that resonance does not occur.
What makes power lines gallop?
Hi gh winds and ice can affect power lines in a way that makes them gallop. Strong winter winds can cause ice to build up on one side of a power line. When this disproportionate buildup occurs, it changes the flow of air around the line, which can then cause it to start bouncing.
What is galloping oscillation?
Galloping is an aeroelastic instability which incites oscillatory motion of elastic structures when subjected to an incident flow. Because galloping is often detrimental to the integrity of the structure, many research studies have focused on investigating methodologies to suppress these oscillations.