National Grid

Electricity is in inquire just about in any place in the civilized world, and in Great britain the network for supplying this electrical power is known ordinarily as the National Grid. The National Grid is an electric power transmission network which connects the substations and power stations. This is so that any electrical vigor generated in Great Britain, can be utilized and help meet vigor demands elsewhere. This grid principles also includes interconnections that run under the sea to northern Ireland Hvdc Moyle, the Isle of Man and France Hvdc Cross-Channel. In Scotland the grid is owned by the Scottish Power, and Scottish and Southern vigor group, and today the National Grid operate these Scottish groups, but the network is owned by Scottish companies.

The electrical vigor generated for the National grid needs to be moved around all parts of the country to furnish the demand. There are two methods available for the transmission and distribution of electric power and these are:
Underground Insulated Cables Overhead Cables (Bare Conductors Suspended at a Safe Height Above Ground)

Cables For Network

The overhead lines are ordinarily used for high-voltage long length transmission, because the cost is lower than underground cables, especially at higher voltages.

Lattice steel towers or 'pylons' are erected to keep the high-voltage overhead transmission lines. The height of the towers is thought about on the need to furnish enough ground clearance of the conductors at maximum sag and deviation caused by swinging in the wind.

The transmission line supports may be constructed from other materials such as, wood, reinforced concrete, steel, or steel lattice towers. Lattice steel towers consist of painted, but more normally galvanized steel members, and are used generally for high-voltage and extra-high-voltage lines. Rolled-steel sections or tubular members are used for these structures. Aluminium alloys are also used as building materials for transmission line supports, as they have the advantage of low weight and resistance from corrosion, but they are more costly than steel.

In British practice, high voltage transmission lines carry voltages ranging from 66kv to 132kv, and extra high voltage lines carry voltages from 220kv to 380kv. In all cases the power is transmitted in the form of three-phase alternating current at 50 cycles/sec, and the cost of an overhead line depends largely on conductor size and voltage.

National Grid