Transmission lines and their feasibility

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Transmission lines have been laid to the furthest corners of our planet. They are an important part of the electric grid systems of every country. They transport electrical energy from generation sites to electrical substations that further divert the electricity to our homes. 

The development of settlements such as cities, villages, and industrial areas has rapidly increased the network of transmission lines. They are the lifeline for the economic development of major financial hubs of the world. Without these most metropolitan cities will struggle to meet their energy demands. 

Long-distance transmission lines need electricity to be transmitted at high voltages for efficiency. It is required because it reduces the loss due to heavy current. 

Their main purpose is to distribute the electricity according to the energy requirements of different regions. The maintenance of these lines is vital for round the clock supply of electricity. 

What Are Transmission Lines Made Of

Overhead transmission lines are manufactured using aluminum alloy strands and they are reinforced by including steel strands. Aluminum is a cheaper alternative to copper and weighs lighter than copper. 

They are not covered with insulation because of being in the air. This requires them to have minimum clearances to operate.

Underground Transmission lines require insulation. They are insulated using PVC, Rubber, Silicon, and in some cases dielectric fluid(oil).

Overhead Transmission Lines and Underground Transmission Lines

Overhead transmission lines are laid with steel pylons. They acquire quite a lot of land area and they need to have special safety lights mounted on them. They are prone to be snapped by high winds or have flashovers because of low temperatures.

They are easier to repair and maintain. If any fault occurs on any part of the line, it can be traced and identified. As these are not covered by any insulation so their thermal capacity is quite high and the line losses are reduced significantly. 

On the other hand, underground transmission cables do not interrupt the construction of human infrastructure. They have lower visibility and they are less affected by the weather. But they have limited thermal capacity so they can operate on higher voltages. They cannot be laid for longer distances because their maintenance will be really expensive. 

If a fault develops, it can be really difficult for the technical teams to trace the fault. The time taken to restore the electricity increases considerably if the cables are underground. 

What Causes Line Losses

The energy generated by the power station is not transferred to the consumers with zero loss. Some of it is lost during the transmission. These losses can be divided into two types: Technical and non-technical losses. 

The technical losses occur due to multiple reasons, the first and foremost is the lengthy transmission lines. This leads to high resistance and i2R losses increase. The haphazard growth of the grid system leads to this and you will also find that the rural electrification is done with these long-distance transmission lines. 

The size of the conductor also affects the line losses. If the size of the conductor is reduced to meet the lower current then the i2R losses can be reduced.