If you know ABC of electrical system then you must be familiar with bulk structures placed in your street or at the corner of your village. This electrical bulk structure is nothing except a Transformer. We have discussed Basics of Transformers
and Working of Transformer
and in current article we'll discuss about the transformer role in electric power supply system and will see if we really need a system based on transformers ?
What is Transmission and Distribution System
A Transmission system is a collection of electrical equipments with cables that deliver power to our home from generating point. To make it more clear lets know these terms :
Generating Points :
Generating points are the sub stations that generate electrical energy from other forms of energy. Examples of generating points are : Thermal Power Plants (Convert Chemical energy of Coal in to Electrical Energy/Electricity), Hydro Power Plant(Converts Potential+Kinetic Energy of Water into Electrical Energy) etc.
Hence, We can say that generating points are those points which converts non-electrical quantities/energies into Electrical energy.
Load Centres :
Load centres are just opposite to the generating points. These are the places where electrical equipments are installed. These equipments consumes electrical energy and known as load.
Now it is clear that a transmission and distribution system is an arrangement that connects generating point to the load points.
Need of Transmission System
Now the question arises that why we waste huge money in building this transmission and distribution network ? A very basic question of electrical engineering.
To understand the importance and role of transmission system one has to know these things :
Generation of Electrical Energy
The generation of electrical energy is related with a famous quote :
More the production less will be the cost per unit.
This is also applicable with the electrical energy production. To reduce per unit cost of electrical energy we have to follow this basic manufacturing rule, have to produce it in bulk.
Larger the production of electrical energy smaller will be the cost of per unit.
To reduce the cost per unit of electrical energy we have to built large power plants and these plants can't be build near human population areas like big cities or in electrical we say it near load centres. Now if electrical power plant can not be built near load centres then we have to bring power from power plant to the load centres and for this we need a transmission and distribution network.
The main reasons why power plant can't built around load centres are :
- Safety Reasons : It is not safe to operate high rating generating equipments near the human residences because a little negligence in safety measures may result in fatal accident.
- Cost of Power Plant Land: Near human population the cost of the land is always high and if we choose this location for power plant then cost of generating electrical energy will increase and our goal will be incomplete.
- Availability of Raw material : Raw material for generation is not available everywhere for example coal. It is found at random places and these are far away from human population, hence this will result in high transportation cost and this results again in increased production cost. Apart from this some fuels like water (in hydro power plant) can not transported hence generating points are normally far from load centres.
Hence the need and importance or significance of transmission system are clear.