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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 does inductive load effect on High Voltage transmission line?
the inductive load which is generally use in high voltage transmission line known as transformer. the transformer transform the high voltage to low voltage.
Why capacitance is neglected in short transmission lines?
Wen the length of overhead transmission line is less than 80 km with an operating voltage up to 20kv it is considered as short transmission lines Due to smaller lengths and low operating voltage the charging current is low so the effect of capacitance of short transmission lines is extremely small and therefore can be neglected as in case of distribution lines and only R L is to be taken into account while analyzing short transmission lines
What is charging current in transmission lines?
Any two conductors separated by an insulating medium constitutes a condenser or capacitor.In case of overhead transmission lines, two conductors form the two plates of the capacitor and the air between the conductors behaves as dielectric medium. Thus an overhead transmission line can be assumed to have capacitance between the conductors throughout the length of the line. The capacitance is uniformly distributed over the length of the line and may be considered as uniform series of condensers connected between the conductors.When an alternating voltage is applied across the transmission line it draws the leading current even when supplying no load. This leading current will be in quadrature with the applied voltage and is termed as charging current. It must be noted that charging current is due to the capacitive effect between the conductors of the line and does not depend on the load. The strength of the charging currents depends on the voltage of transmission, the capacitance of the line and frequency of the ac supply. It is given by the expressionSignificance of Charging currents:Capacitance effect (responsible for charging currents) of the short transmission lines are negligible. However they are significant in medium and long distance transmission lines.In long distance transmission lines, during light loaded conditions receiving end voltage will be higher than sending end voltage. This is because of the charging currents and capacitive effect of the line
What is surge impedance in power systems?
Actually surge impedance is present in a transmission line due to the capacitance of transmission line. Now this capacitor attends the reactive power of the transmission line to energise its magnetic flux. now due to the flux the impedance will increase and the power is reactive too. due to the impedance loss is more.
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]
Why is it dangerous for connect an alternator with high capacitance transmission line?
It is dangerous because with capacitive load line voltage will increase which cause the line voltage difference and it will not satisfy the parallel operation of the same voltage rating.
What does inductive load effect on High Voltage transmission line?
the inductive load which is generally use in high voltage transmission line known as transformer. the transformer transform the high voltage to low voltage.
What is the methods of improving string efficiency in transmission line?
capacitance grading method,static shielding
Why capacitance is neglected in short transmission lines?
Wen the length of overhead transmission line is less than 80 km with an operating voltage up to 20kv it is considered as short transmission lines Due to smaller lengths and low operating voltage the charging current is low so the effect of capacitance of short transmission lines is extremely small and therefore can be neglected as in case of distribution lines and only R L is to be taken into account while analyzing short transmission lines
What is line charging in transmission?
Transmission Line Charging To initially charge the transmission line, the generator voltage stably controlled from 30% of the rated voltage to 110% of the rated voltage by using AVR. The change-over switch (43CH) for initial transmission line charging is mounted on the operator's desk in the main control room.This Voltage Changes are required because of the Stray capacitance effect at the charging and boosts the Voltage at the other end and the inductance of the line drops the Voltage soon after charging
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 is charging current in transmission lines?
Any two conductors separated by an insulating medium constitutes a condenser or capacitor.In case of overhead transmission lines, two conductors form the two plates of the capacitor and the air between the conductors behaves as dielectric medium. Thus an overhead transmission line can be assumed to have capacitance between the conductors throughout the length of the line. The capacitance is uniformly distributed over the length of the line and may be considered as uniform series of condensers connected between the conductors.When an alternating voltage is applied across the transmission line it draws the leading current even when supplying no load. This leading current will be in quadrature with the applied voltage and is termed as charging current. It must be noted that charging current is due to the capacitive effect between the conductors of the line and does not depend on the load. The strength of the charging currents depends on the voltage of transmission, the capacitance of the line and frequency of the ac supply. It is given by the expressionSignificance of Charging currents:Capacitance effect (responsible for charging currents) of the short transmission lines are negligible. However they are significant in medium and long distance transmission lines.In long distance transmission lines, during light loaded conditions receiving end voltage will be higher than sending end voltage. This is because of the charging currents and capacitive effect of the line
How the section of a transmission line can be used as lumped circuit element?
Actually in networks we will consider the elements like resistance, inductance, capacitance as lumped elements for simplicity, like this in power systems we will consider the transmission line parameters(resistance, inductance, capacitance) as lumped elements, because we will calculate all the parameters of power systems with respect to receiving end or sending end but not with respect to middle of the line. If a fault occurs on transmission line then we should not consider the lumped elements of that total transmission line, we should consider the lumped elements from sending end to the point where the fault is occurred.
What is surge impedance in power systems?
Actually surge impedance is present in a transmission line due to the capacitance of transmission line. Now this capacitor attends the reactive power of the transmission line to energise its magnetic flux. now due to the flux the impedance will increase and the power is reactive too. due to the impedance loss is more.
High voltage transmission line in India?
ge transmission in india
For a transmission line the characteristic impedance with inductance 0.294mHm and capacitance 60pFm?
= Zo = sqrt(L/C) = sqrt(0.294e-3/60e-12) ~ 2214 ohms =
