Electricity is the most convenient form of energy. Like the genie from "Aladdin’s Magic lamp," at the flick of switch electricity is ready to do anything at the master's bidding. How do we generate this genie, electricity? What are the defining characteristics of the electricity we use?
“Nothing is too wonderful to be true if it be consistent with the laws of nature.”
Michael Faraday
The History of Electrical Generation
The principle of electromagnetic induction is the basis of the generation of electricity.
Discovered in 1830 by Michael Faraday, this later led to the development of the dynamo by Pixie. This started the generation of electricity by converting mechanical energy from steam turbines and hydro turbines. Be it the generation of a few watts of electricity or millions of watts (mega watts) of electricity, the basic principle remains the same.
The Basics of Generators
In its simplest form the electric generator consists of
- A magnet that produces a magnetic field.
- A movable copper conductor placed at right angles to the magnetic field,
When the copper conductor moves, the conductor cuts the magnetic field. This produces an emf (electromotive force) or voltage, which sends an electric current through the copper conductor.
Mechanical energy moves the coil converting it to electrical energy.
Modern Electrical Generators
In real life, the electric generator is slightly different.
- The magnet is an electromagnet and it rotates. This is the 'rotor' or the 'field' and consists of wound conductors on the rotating part of the generator.
- The copper conductor is stationary called the ' stator' or the 'armature'. This consists of high current carrying copper coils wound on the stationary part of the generator.
- The rotor's rotating magnetic field cuts the stationary stator copper conductors to produce the electric current.
- The energy for rotation of the rotor is from a rotating turbine or an Internal Combustion engine.
All generators use this basic principle. Only the primary energy source and prime mover is different. The prime mover can be a steam turbine, a gas turbine, a wind turbine, or a hydro turbine.
One very important factor about electric generators is their synchronised operation.
All the power plant generators connect to the national or the regional transmission grid. The domestic, public, or industrial users get the electricity from this grid. This means all these generators should produce electric power that has the same characteristics.