The basic definition for transposition of transmission line is to rotate the conductors which result in the conductor or a phase being moved to next physical location in a regular sequence. In electrical power transmission lines, the conductor arranges unequal space. So the voltage drops are not same as one place to another. To eliminate this effect can simply do by interchange the conductor position which is known as transposition. When the transmission line is more than 100 km long, then, as per electrical requirements three phases needed to be transposed. The transposition arrangement is much necessary which there is a capacitance between the power conductor. When the high voltage applied capacitance created between the conductors and conductor and ground.
Features of transposition of transmission line
transposition of transmission line are used to transpose the phase conductors in three sections in such a way that each phase by rotation occupies each of the three phase positions in a circuit. In another transposition arrangement called ‘on span transposition’.
The transposition power line arrangement is also which carried out near a high tension tower due to greater ground clearance which available near the overhead tower than in the mid-span. Two multiple tension insulator strings are connected back-to-back through a strain plate.
In the central phase strain plate, a single suspension insulator string having almost doubled the no. of insulator discs and air gap distance is suspended. The balance work comprises placement of jumpers.
Theory Behind the Transposition of the Conductors
The transposition arrangement of the conductor can simply show in the following the figure. The conductor in Position 1, Position 2 and Position 3 changes in a specific arrangement to reduce the effect of capacitance and the electrostatic unbalanced voltages.
Why Transposition Arrangement is Use
The transposition under power lines reduce the electrostatic unbalance among the three phases. it also used to stabilize the voltage unbalance.
The transposition arrangement of high voltage lines also helps to reduce the system power loss.
In addition to this, we have developed Transposition System for Single circuit tower using same tension tower with reduced deviation angle.
Transposition arrangement of power line also helps to reduce the effect of inductive coupling.
So would be benefited by reducing one more tower design, approval, and results in a reduction of overall project time, etc.
It is proved more economical Solution, in comparison of the conventional transposition system.
Approach for Transposition arrangement
With the continuous increase in demand for power, a lot of new transmission line project are coming, and simultaneously it has become very important to Complete the line in shortest possible time.
For lines longer than 100 km to 150 km, transposition of phases carried out with a special tower, to reduce electrical line losses.
There is need to adopt different approaches of transposition arrangement, which is not only cost effective but also It can
save the execution time with reduced engineering activity. The new method proposed herewith basically simplifies the engineering activity, and expedites the project completion Following are the main aspect of the Proposed method of transposition.