Transposition of Conductors

Definition: The transposition process involves physically rotating the conductors so that each conductor takes up the next position in a regular sequence. This equalizes the mutual inductance and capacitance between the lines. The irregular spacing between the conductors results in a complex value of inductances, which complicates studying the power system. Transposition is typically carried out at switching stations and substations. The transposition cycle is illustrated in the figure below.


Needs of Transposition of Conductors

The inductance of an unsymmetrical line can cause voltage drops even when the voltage is balanced. This is because the magnetic field exists in the conductor due to the inducing voltages, leading to interference in the line. To minimize this interference, we can continuously exchange the position of the conductor, which can be achieved by transpositioning the conductors.

Transposition Method

To balance the voltage on a power line, it’s important to balance the capacitance of the line. This can be achieved by transpositioning the lines. Transposition involves placing the one-third segment of all three conductor phases in the same line. This balancing technique effectively reduces voltage imbalances on the line.

Disadvantage of Transposition of Conductors

Frequently altering the position of conductors can weaken the supporting structure, increasing system costs.


In conclusion, understanding the process of conductor transposition is crucial for optimizing the efficiency and safety of electrical systems. Implementing proper transposition techniques can mitigate electromagnetic interference and ensure a balanced voltage distribution.

Reference: Transposition of Transmission line-Wikipedia

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