0
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 expression
Significance 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 else can I help you with?
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
How are step-up and step-down transformers used in the transmission of electric current from the electric company to homes?
(This is what my teacher said, I wrote this down in my notes) The answer is, Step-up transformers are used to increase the voltage of an electric current before it is sent out over transmission lines from the electric company. Step-down transformers are used to reduce the voltage of current from high-voltage transmission lines before it enters homes and businesses. Some devices, such as televisions, contain step-up transformers that increase the voltage once again.
Why there are no losses in DC transmission?
There are losses in d.c. transmission lines, due to their resistance. But there are no reactive losses. So, d.c. transmission lines have less losses in comparison to an equivalent a.c. transmission line.
Why transmission lines are transposed?
To avoid inteference between communication lines
Why is energy lost in power transmission lines?
Increase the voltage in the lines.
What are examples of an electric current?
Transmission Lines are an example of electic current
What are some properties of current electricity?
transmission lines
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 are some examples of an electric current?
Transmission Lines are an example of electic current
Why do transmission lines use alternating current?
Transmission lines use alternating current in order to support stepping-up and stepping-down of the voltage with transformers. Voltage is stepped-up at the power station, sent over the transmission lines, and stepped-down at the receiver. (This is a simplified explanation.) By stepping-up, you reduce the current carrying requirement of the lines, and they can thus be smaller.You could not do this with direct current as transformers only work for alternating current.
What is the formula for calculating power loss in transmission lines?
The formula for calculating power loss in transmission lines is Ploss I2 R, where Ploss is the power loss, I is the current flowing through the transmission line, and R is the resistance of the transmission line.
What are some example of current?
One example of current electricity are transmission lines. These bring electricity from power stations to individual houses.
Advantages in Corona in transmission lines?
The virtual diameter of the conductor becomes greater to carry more current
What does power loss in electrical transmission mean?
The term, 'power loss', describes the rate of energy losses caused by the load current in the transmission lines
What are the different charging processes?
The different charging processes include constant-current charging, constant-voltage charging, and trickle charging. Constant-current charging delivers a consistent current to the battery until a certain voltage is reached, then switches to constant-voltage charging to prevent overcharging. Trickle charging is a slow, low-level charge that helps maintain a battery's full capacity over time.
Is current transformer is a distribution transformer?
In transmission lines there is a massive current, we use CT to make this current measurable i.e. it steps down the current but DT is used to step down the voltage
What are the examples of electricity?
One example of current electricity are transmission lines. These bring electricity from power stations to individual houses.
