CHAPTER 3: ELECTROMAGNETISM3.5 Generation and Transmission of Electricity

Prepared by:Qhaiyum Shah, Nur Hawasari & Mohd Shahfie

SMK Sandakan (Bestari)5 KRK’14

Introduction Electricity is generating in power stations by huge machines called generators. The energy

transformation which takes place in a power station.

Generation of Electricity Electrical energy can be generated from different sources of energy. This energy from different

sources may be renewable or non-renewable.

Renewable Sources

Non-Renewable Sources

NUCLEAR ENERGY PETROLEUM

Transmission of Electricity Electrical energy which is generated by alternators in a power station needs to be transmitted to

the users in towns and industrial areas by cables.

Problems in Electricity Transmission

Problems Ways to overcome Pictures

1. Cost of cables. a) Copper cables have low resistance but are high in cost.b) Aluminium cables are usually used because they are light,

have low resistance and cost less.

2. Loss of power by the cables.

a) By using thicker aluminium cables, resistance of the cables can be reduced.

b) By using high voltage transmission, the current in the cables is reduced and hence the power dissipated by the cables is reduced.

3. Charge leakage between the cables and the Earth.

a) To prevent charge leak, the aluminium cables are supported by high metal pylons.

b) The metal support of the pylon is earthed so that it is safe to workers and the public who come into contact with them.

National Grid Network The National Grid Network is a system of cables which connects all the power stations and sub-

stations to all the consumers in a close-loop.

Step-up transformers are used to increase the output voltage of a generator. The high voltage is need to reach the sub-stations in areas such as towns, cities and industrial areas.

In the sub-stations, step-down transformers are used to reduce the output voltage for light industrial areas, offices and our homes.

Advantages of National Grid Network

Power supply will be uninterrupted even when there is a breakdown in one power station. The other power station will increase their production to ensure continuous power supply.

The generation of electricity by each station can be controlled and regulated according to the demand pattern.

Cost of generation of electricity is reduced.

That’s AllFrom Us,

Thank You For Listening ! XD