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What is the Transposition of Transmission Line?


The transmission and distribution course is very interesting. There is a lot to know about transmission lines. When we travel to the countryside, we see transmission lines in the middle of green fields. Which is very much eye soothing. Today we will discuss the transposition of transmission line.

War of Power Line and Telephone Line

Have you ever wondered, if there is any telephone line or mobile tower beside a high voltage transmission line, what will happen? Maybe some of you have thought about it. Mainly transposition technique is used for avoiding the effect of telecommunication lines on the power lines. Today we will know briefly about it. 

Transposition of Transmission Line

Transposition means exchanging. To reestablish the unbalanced three-phase line of unequal distance, there is a system of exchanging places at a specific distance for each wire. This system of exchanging places of the transmission line is called transposition. The average inductance of each wire is equal because of transposition.

transposition of transmission line
Transposition System of Transmission Line

Objectives of Transposition 

The value of each line constant (resistance, inductance, capacitance) can be different because of the unequal distance of three-phase overhead line wires. Which affects the regulation of transportation lines and transmission capacity.

To avoid this type of effect, overhead lines are transposed. Practically, the transposing system should be like this, each line can be transposed between 1/3 of its total length. Another reason is, to solve the inductance fault of the transmission line caused by the telecommunication line. 

Advantages of Transposition System

  • Reduces interference of telephone line or mobile tower by line transposition. 
  • To supply balance power to sending or receiving end of the transmission line, line transposition is used.
  • Because of transposition, the telephone line is transposed by 150 meters frequently. 

What Problems Can Occur without Transposition 

  • Line calculation is difficult for different values of line constants. 
  • Because of line regulation and supply skills, there is a reactive effect on skill. 
  • Electromagnetic radiation from mobile, radio towers affects transmission line inductance. 

So we can say that there is no way better than a transposition system to control transmission line voltage regulation, and efficiency. It is a very effective process also.

That’s all for today’s topic transposition of transmission line.

Hope now you understand transposition of transmission line.

You can also read: Measurement of 3 Phase Reactive Power and Theory