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Capacitors are formed by placing two conductors near each other. Usually, they are plates separated by an insulating dielectric. The capacitance is a function of the area and closeness of the plates. Bundled conductors have capacitance for the same reason - they are conductors close to each other. Since capacitors work by transferring charge (remember that the equation of a capacitor is dv/dt = i/c) then a signal on one conductor can induce a "copy" of the signal on the other line - usually a faint copy, but a copy nontheless. This induced voltage effect is also known as interference, and must be considered in the final system design.
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Why 400kVA and above the transmission line have bundled conductor?
To reduce the electric field intensity at the surface of the conductor which can lead to corona discharge and insulation breakdown. By using bundled conductors, the electric field is distributed between the four (in the case of 400-kV lines) conductors, thus reducing the field intensity per conductor.
How capacitance effects are taken into account in transmission lines?
Natural capacitance exists between conductors at different potentials, including between those conductors and earth (ground). The value of such capacitance is significantly higher with underground cables than with overhead lines, due to the close proximity of the individual conductors in an underground cable. Capacitance results in line losses in both a.c. overhead and underground systems, due to the corresponding capacitive reactance (opposition to a.c.). In the case of long, high-voltage, underground or under-sea cables, the capacitance losses can be so high that d.c. transmission is used instead of a.c. (d.c. eliminates capacitive line losses). In addition to the line losses, the electric fields resulting from the capacitance can lead to insulation breakdown -making it essential that 'sharp corners', etc., are avoided in their design and construction. One of the reasons that high-voltage overhead conductors are 'bundled' (i.e. more than one conductor per line) is to reduce the stress on individual line conductors that would otherwise occur due to their relatively small diameters.
What are the Advantages of bundle conductors in transmission lines?
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.
What is the purpose of a phase conductor?
There is no such thing as a 'phase conductor'; the correct term is 'line conductor'. In a single-phase system, the line conductor is the energised conductor; in a three-phase system, there are three (energised) line conductors.
What is the methods of improving string efficiency in transmission line?
capacitance grading method,static shielding
Why 400kVA and above the transmission line have bundled conductor?
To reduce the electric field intensity at the surface of the conductor which can lead to corona discharge and insulation breakdown. By using bundled conductors, the electric field is distributed between the four (in the case of 400-kV lines) conductors, thus reducing the field intensity per conductor.
How capacitance effects are taken into account in transmission lines?
Natural capacitance exists between conductors at different potentials, including between those conductors and earth (ground). The value of such capacitance is significantly higher with underground cables than with overhead lines, due to the close proximity of the individual conductors in an underground cable. Capacitance results in line losses in both a.c. overhead and underground systems, due to the corresponding capacitive reactance (opposition to a.c.). In the case of long, high-voltage, underground or under-sea cables, the capacitance losses can be so high that d.c. transmission is used instead of a.c. (d.c. eliminates capacitive line losses). In addition to the line losses, the electric fields resulting from the capacitance can lead to insulation breakdown -making it essential that 'sharp corners', etc., are avoided in their design and construction. One of the reasons that high-voltage overhead conductors are 'bundled' (i.e. more than one conductor per line) is to reduce the stress on individual line conductors that would otherwise occur due to their relatively small diameters.
What are the Advantages of bundle conductors in transmission lines?
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.
What is the purpose of a phase conductor?
There is no such thing as a 'phase conductor'; the correct term is 'line conductor'. In a single-phase system, the line conductor is the energised conductor; in a three-phase system, there are three (energised) line conductors.
Could it be dangerous to connect an alternator to a long transmission line if the line had a high capacitance?
Yes. Because... If we connect an alternator to a transmission line of high capacitance the line voltage will increase and caused a line voltage difference, which does not satisfied the condition of parallel operation of same voltage rating. [By Akhtaruzzaman08]
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.
What is phase conductor?
There is no such thing as a 'phase conductor'. The correct term is 'line conductor'. Line conductors are the three energised conductors that supply a three-phase load.
What is the effect if capacitance in transmission line is high?
higher phase shift lower impedance
What two factors determine the capacitive reactance of a capacitor?
capacitive reactance is inversely proportional to the capacitance of the capacitor and frequency of the AC line reactance (in ohms) = 1/(capacitance * frequency)
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 the methods of improving string efficiency in transmission line?
capacitance grading method,static shielding
What ACSR conductor is used for 33kV transmission line?
Single Circuit PantherACSR Conductor
