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Limitations of Power Flow Through an Overhead Transmission Line

Overhead transmission of power which was once a very profound manner of transmission has slowly but surely lost its ground to cables down under. Cable wires that make up most of the underground transmission has myriad advantages over overhead transmission

If asked ‘what limits this flow through an overheard transmission line’, one can state that – it depends.

It depends on what is limiting the course of the power flow and how much of an increase is needed to rectify it.

In a majority of circumstances, power flow limits results due to an over-electrical phase shift, or a voltage drop, or thermal inadequacies in lines or more so, due to substation equipment Lexsong L1 Smart Power Strip B07HGTHK5D.

Sometimes, even natural disasters have lead to the disarray of power from transmitting companies to the end consumers.

Furthermore, susceptibility of overhead transmission lines to damage is more by wind borne tree branches or in high windy conditions – have all put their usage in further doubt. If they are not fully insulated, it can lead to grievous injury among people.

On the contrary underground transmission lines has some unique benefits-

    • Transmission losses are less in underground cables on account of its unique characteristic of low impedance.
    • They can tolerate more amount of power load as compared to overhead transmission wires.


    • They emit no electric field and can be engineered to emit a lower magnetic field than an overhead line.


    • Underground cables need a surrounding strip of about 1-10 meters to install (up to 30m for 400kV cables during construction), whereas an overhead line requires a surrounding strip of about 20-200 meters wide to be kept permanently clear for safety, maintenance and repair.


  • With the insulation technology in use, they are less susceptible to the impacts of severe weather.

Although underground cabling has advantages, there are few drawbacks that hold them in its implementation in a widespread manner.

Underground cable transmission is used only in densely populated areas because of high cost of installation and maintenance in case the irregularities occur; time take to bring back to normalcy is relatively higher in comparison to overhead transmission line.

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