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What are the Advantages of bundle conductors in transmission lines?
Wiki User
∙ 12y ago
High voltage transmission lines can transmit more power when the total impedance of the line is lowered. Inductive reactance is typically ten times larger than the series resistance of a conductor. Bundling drastically decreases the reactance of the largest component of impedance, the reactive inductance, and adding a second conductor also cuts real energy losses by one half because the resistance is reduced by one half. I squared X losses are reduced which means that the voltage drop along the line is reduced.
AnswerThere is a limit to how much electric field intensity an individual conductor can withstand. This is greatest at the surface of the conductor. Even in dry air, ionisation may result causing corona discharge to take place, and may lead to a breakdown in insulation where the conductor is supported from its tower.
Transmission line conductors, therefore, are bundled in order to reduce the electric field intensity which would be excessive if a single conductor were to be used instead. With bundled conductors, the same field is distributed equally between the bundled conductors, reducing the field intensity per conductor.
Wiki User
∙ 12y ago
Wiki User
∙ 12y agoYour question is confusing, to say the least. Are you asking "What is the benefit of a polyphase (three-phase) system compared with a single-phase system?", or are you asking why polyphase transmission line conductors are 'bundled'?
If the former, then the answer is that, for a given load, a three-phase transmission system uses significantly less volume of copper than a corresponding single-phase system and, so, is more economical.
If the latter, then conductors are bundled in order to reduce the electric stress that would, otherwise, be placed on a single conductor.
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Why dampers are used at the end of tower in transmission lines?
To 'damp' vibrations in the conductors.
What is the difference between bundled conductors and composite conductors?
Bundled conductors are used to reduce the effect of corona. As in place of a single conductor. two conductors are used in parallel the voltage gradient build up is less and thus the ionisation of the surrounding air is decreased. Therefore the effect of corona is reduced.
Why do power transmission lines not have neutral conductor?
No neutral is necessary, because the transmission line's line currents are roughly balanced and, so, the phasor sum of those currents will be relatively insignificant, rendering the need for a neutral conductor to be an unnecessary expense. In practise, for most transmission towers, each of the three 'lines' comprises not just a single conductor but, rather, a number of conductors which are bundled together in order to reduce electric stress surrounding the line. The number of conductors per bundle increases with transmission voltages. In the UK, for example, 400-kV transmission lines normally comprise bundles of four conductors, whereas 275-kV transmission lines normally comprise bundles of two, and 132-kV lines just one. Running along the top of transmission towers is an earthed conductor, called a 'guard conductor', whose function is to protect the lines from lightning strikes during electrical storms. Many transmission towers also have two, separate, three-phase circuits -one circuit on each side of the tower. But, definitely, no neutral!
How many wire are used in transmission line?
Transmission lines are three-phase systems. There are three line conductors in a three-phase system. However, to reduce electric stress at higher voltages, these lines are frequently made up of 'bundled' conductors -so each line might have two, three, or four separate conductors. In addition, transmission towers usually carry separate circuits -i.e. separate three-phase circuits on opposite sides of each tower. So, in the UK for example, a typical 400-kV transmission line will consist of two, separate, three-phase circuits suspended on each side of each tower, with each line consisting of four bundled conductors. That's 24 conductors.
How do you reduce radiation loss in transmission lines?
Transmission loss reduce by using 1) higher diameter conductor (R = q l / a) or specially maded low loss conductors 2) using energy efficient equipment such as low loss transformer 3) twisted conductors instead of solid 4) proper monitoring and control of transmission eqipment 5) use of high temperature super conductors ....etc
What are bundled conductors?
High-voltage transmission line conductors are 'bundled' -that is, each 'line' comprises two or more conductors, rather than a single conductor, suspended from each insulator chain. The reason for bundling is to reduce the intensity of the electric field on the surface of the conductors (the same field is shared between the surfaces of several, rather than just one, conductors), which would otherwise result in a breakdown of the insulating property of the air immediately surrounding a single conductor. In the UK, 400-kV transmission lines use a bundle of four conductors per line, and 275-kV transmission lines use a bundle of two.
Is three phase transmission line is example of bundle conductor?
'Bundled' conductors describe a line in which two or more conductors are supported from the same insulator chain. In the UK, 275-kV transmission lines typically use two conductors per line, and 400-kV transmission lines typically use four conductors per line. The purpose of bundling conductors is to spread the electric stress on the conductors (e.g. for four conductors, the same amount of electric flux will be 'shared' between the four conductors, rather than concentrated on the surface of one conductor).
What is definition of transmission lines?
Conductors that transmit an electric signal.
What are some advantages to using super-conductors as electric transmission lines?
Super-conductors have zero electrical resistance, allowing for highly efficient electricity transmission over long distances without energy loss. They can carry much higher amounts of electricity compared to traditional copper wires, potentially reducing the need for multiple transmission lines. Super-conductors also require less maintenance and have a smaller footprint, making them suitable for urban areas.
Why dampers are used at the end of tower in transmission lines?
To 'damp' vibrations in the conductors.
What is the difference between bundled conductors and composite conductors?
Bundled conductors are used to reduce the effect of corona. As in place of a single conductor. two conductors are used in parallel the voltage gradient build up is less and thus the ionisation of the surrounding air is decreased. Therefore the effect of corona is reduced.
What is purpose of using bundle conductors in ehv transmission lines?
One reason is that since the electrons travel on the surface of the transmission lines there is more surface area when conductors are bundled thereby reducing resistance to current flow thereby reducing the voltage drop across the transmission path. In extra high voltage line an electrical discharge formed by ionization of fluids surrounded by the conductor which is highly energized , so energized that it creates electrical conduction but not high enough to electrical breaking or arcing surrounding objects. this phenomenon is called corona losses.to prevent this corona loss bundle conductor is used.
Why do power transmission lines not have neutral conductor?
No neutral is necessary, because the transmission line's line currents are roughly balanced and, so, the phasor sum of those currents will be relatively insignificant, rendering the need for a neutral conductor to be an unnecessary expense. In practise, for most transmission towers, each of the three 'lines' comprises not just a single conductor but, rather, a number of conductors which are bundled together in order to reduce electric stress surrounding the line. The number of conductors per bundle increases with transmission voltages. In the UK, for example, 400-kV transmission lines normally comprise bundles of four conductors, whereas 275-kV transmission lines normally comprise bundles of two, and 132-kV lines just one. Running along the top of transmission towers is an earthed conductor, called a 'guard conductor', whose function is to protect the lines from lightning strikes during electrical storms. Many transmission towers also have two, separate, three-phase circuits -one circuit on each side of the tower. But, definitely, no neutral!
Why is a sag provided in the transmission line?
Sag is provided in transmission lines in order to lessen the tension of the transmission lines. Sag literally means to be bend in shape. In overhead transmission lines , the difference in level between points of supports (towers or utility poles) and the lowest point on the conductor is called a sag. Explanation: While erecting an overhead line, it is very important that the conductors are under safe tension. If the conductors are too much stressed between the supports ( towers, utility poles), then the stress on the conductors may reach to an unsafe level and the conductor may break due to excessive pressure ( i,e tension). in order to permit safe tension in the conductors, the conductors ( i.e the transmission lines) are not fully stretched but are allowed to have a dip or a sag.
What is transposition of a transmission line?
The balancing effect on account of irregular spacing of conductors can be avoided by changing the position of the conductors at regular distances. this is called transposition of conductors. In case of 3- phase transmission lines, the inductance and capacitance of each phase will be different if the three conductors are spaced differently (each phase to the other two phases, and each phase to ground). the apparent resistance of the conductors is also affected on account of transfer of power between the phases which occur due to mutual coupling. so all the three parameters of the transmission lines are affected by irregular spacing of the conductors.
What has the author Sidney Frankel written?
Sidney Frankel has written: 'Multiconductor transmission line analysis' -- subject(s): Electric conductors, Multiconductor transmission lines
Why phases in a transmission line need to be transposed?
Transposition means exchanging of the position of the transmission line after equal distances. Even if the voltage across the conductors are equal during the transmission, there will be slight differences and will result in varied inductances of the conductors. Hence if we have symmetrical conductors running through transmission line in a similar fashion, there may be unbalances in voltage. Also mutual inductances vary for untransposed lines.
