Underground cables are those which are buried under soil and used to transmit power from generation plants to substations or from substation to distribution centre or from distribution centre to house of consumers.
There are many advantages of using underground cables than that of the overhead lines. That’s why even though of huge costing, underground cables are used for transmission and distribution purpose.
After the initial expenditure, the underground cables have very less maintenance cost and they have long life.
The power loss in underground cable is less than overhead lines and these can absorb emergency power fluctuations.
Another property of underground cables is that they don’t emits any electric field, which implies that there is no corona loss and proximity effect which reduces the effective resistance of the network and therefore reducing the losses.
As the cables lie under the ground so they are immune to external changes i.e. wind, ice etc., which ensures the long life and fault less power distribution.
All the cables are kept adjacent to each other and covered with a thick insulator which indicates that the underground cables take less space than overhead lines.
Underground cables are ideal for transmission purpose in populated areas because of the deficiency of space and it also increases the safety of the nearby consumers.