Electricity Transmission and Distribution System

• The components of the electricity transmission and distribution system are:
• National Grid Network
• switch zone
• transformer station
• main substation
• branch substations
• Electrical energy is distributed from power stations to consumers through a network of cables that is called the National Grid Network. In this network, electrical energy is combined and then distributed to the consumers in an orderly and efficient mannner.
• The advantages of the national grid network include:
• Extra electrical energy from a power station in a particular area can be channeled to an area with higher demand.
• It ensures that electricity supply to consumers is not disrupted when a power station breaks down.
• Some power stations can be closed when demand is low and re-opened when demand is high.This will help save running costs and prevents wastage.
• Power stations produce electricity at a voltage of 11 kV.
• Step-up transformers are used to raise the voltage to 132 kV, 275 kV or 500 kV to reduce power loss while transmitting the current through cables.

Switch Zones

• Switch zones are located at several locations in the network.
• They are used to control the electrical energy in the network and channel it to designated areas.
• Each switch zone is equipped with 'switches' electrical energy leaving the power station can be controlled.

Main Substation and its Branches

• From the grid network, electricity is passed to the main substation.
• Here, the electric voltage is reduced to 11 kV 33 kV.
• The electricity is then sent to the branch substations or straight to heavy industrial areas.
• At the branch substation, the voltage is further reduced to 240V or 4I5V before it is distributed to consumers.