Electromagnetic induction was discovered by Michael Faraday in 1831. Faraday found that if a conductor “cuts across” lines of magnetic force, or if magnetic lines of force cut across a conductor, a voltage, or EMF, is induced into the conductor.
Most electricity is currently generated by magnetic induction through devices known as generators.
Electricity Generation by Magnetic Induction
Most electricity is currently generated by magnetic induction through devices known as generators. A generator is a machine that converts mechanical energy into electrical energy by using the principle of magnetic induction. Magnetic induction is used to produce a voltage by rotating coils of wire through a stationary magnetic field, or by rotating a magnetic field through stationary coils of wire.
For example, a typical turbo-alternator in nuclear power plants consists of:
- Main generator
- 4-pole hydrogen-cooled rotor. The rotor winding is made up of hollow conductors through which the hydrogen gas flows. The hydrogen is cooled in the hydrogen/water heat exchangers.
- Stator with water-cooled winding (demineralized water).
Brushless excitation system. Shaft-driven, air-cooled brushless exciter. The exciter keeps a current going through the wires of the rotor. When this rotor turns, it induces a voltage in the stator.