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What is the voltage in long transmission lines?
When the length of an overhead transmission line is more than 150 km and the line voltage is very high (more than 100 kV), it is usually considered as long transmission line.
How is voltage regulated in a transmission line?
Voltage regulation in transmission lines occurs due to the impedance of the line between its sending and receiving ends. Transmission lines intrinsically have some amount of resistance, inductance, and capacitance that all change the voltage continuously along the line.
What are standing waves in transmission lines?
Standing waves are waves of voltage and current which do not propagate (i.e. they are stationary), but are the result of interference between incident and reflected waves along a transmission line. A node is a point on a standing wave of minimum amplitude. An antinode is a point on a standing wave of maximum amplitude.
What is meant by travelling waves in transmission power lines?
Travelling wave on transmission line is the voltage / current waves which propagate from the source end to the load end during the transient condition. These waves travel along the line with the velocity equal to velocity of light if line losses are neglected.
How are voltage and current measured on a transmission line?
Figure 2: Transmission line circuit, distance measured from the load to the source In terms of the distance d away from the load, the magnitudes of the voltage and current can be expressed as The magnitudes of the voltage and current waves for a short-circuited load are shown in Figure 3.
What causes a standing wave on a transmission line?
Remember: Standing wave is created due to interference between the traveling waves (incident & reflected) When lossless! We are interested to know what happens to the magnitude of the |V| as such interference is created!
How does a sinusoidal voltage drive a transmission line?
A sinusoidal voltage source with its source impedance drives a lossless transmission line with characteristic impedance ZC, terminated in a resistive load RL. The magnitudes of the voltage and current along the line at any distance z away from the source are [1]: