How do you protect transmission lines from lightning?
Measures to increase the lightning withstand level of a transmission line and reduce lightning related hazards include: decreasing grounding resistance of towers; adjusting protection angle of the shield wire; using a lightning protection differentiation design for double circuit towers; installing additional lightning …
Do transmission towers get struck by lightning?
Lightning myths and facts to keep you safe in severe weather Like trees and other tall objects, transmission poles are likely to intercept lightning strikes, but they do not attract lightning.
How are towers protected from lightning?
Direct strike protection Antennas which form the highest point of the structure and are not at tower potential are particularly vulnerable and it is difficult to protect these effectively. High-gain whip antennas mounted at tower top are typical examples. The best form of protection is to carry some spares.
What happens when lightning strikes a transmission line?
Lightning Strikes to the Transmission Line. The lightning strike injects a current into the power system when it hits a transmission line. The magnitude of the generated voltages depends on the current waveform and the impedances through which it flows. The steepness of the voltage wave governs the insulation flashover …
Why lightning discharges will cause faults in transmission line?
Transmission lines from lightning strike is mainly due to the condition of lightning strike to make transmission line insulator is punctured, the insulation of the line moment less, cause the wire connection to earth potential hardware, discharge of cross arm, or along the insulator flashover, residual until …
What is earthing screen?
Earthing screen: It consists of a network of copper conductors (generally called shield or screen) mounted all over the electrical equipment in the substation or power station. The shield is properly connected to earth on at least two points through a low impedance.
Why lightning discharges will cause faults of transmission lines?
What are lightning rods made of?
The main attribute common to all lightning rods is that they are all made of conductive materials, such as copper and aluminum. Copper and its alloys are the most common materials used in lightning protection.
Why lightning discharges will cause faults of transmission line?
What is flashover voltage in transmission lines?
flashover in Electrical Engineering In electric power transmission, a flashover is an unintended high voltage electric discharge over or around an insulator, or sparking between two or more adjacent conductors.
What are the factors that influence the lightning induced voltage on transmission line?
The ground conductivity influences significantly the magni- tude and the polarity of the electromagnetic field radiated by the lightning as it propagates over the ground and hence the induced voltage on overhead lines. The induced voltage on the overhead conductors also depend on the nearby lightning strike location.
How are lightning strokes on transmission lines classified?
When a thunder cloud directly discharges onto a transmission line tower or line wires it is called a direct stroke. This is the most severe form of the stroke. However, for bulk of the transmission systems the direct strokes are rare and only the induced strokes occur.