Fundamentals and basics of electricity generation were discovered
by the British scientist Faraday since the year 1820.
Electricity practically generated at power station by
electromechanical generator which convert the kinetic energy to electrical
energy, this kinetic energy may resulted from some type of sources like, heat
engines fueled by chemical combustion or nuclear reactions or water flow or wind flow …etc. Also in some types of
power station electrical energy may be generated from solar energy
(photo voltaic) or geothermal power.
After the electricity is generated, Electric Utilities precede in
the two second steps to deliver the electricity to the consumer which called
Transmission and distribution.
The question is…… How the electricity is generated in the
electromechanical generator?
According to Faraday Law, when a loop of wire or a disk of copper
move between the poles of a magnet, electrical current will generated in this
loop or copper disk.
This is the basic idea of how generator create electricity, as the
generator contain wire wingdings called armature which is stationary and a
magnetic field rotates around this armature so electrical current and
voltage gets generated in the armature winding which is connected directly to
the load.
The magnetic field is generated practically from the exciter which
consider as apart of generator. This exciter supply direct current to the
generator field winding to magnetizing the rotating poles and sets up a steady magnetic field. The exciter is controlled by a
voltage regulator; there are two types of exciters:
1-Bruch type with a movable commutator.
2-Static excitation or also called brushless exciter.
The resulted current and voltage waveforms at the generator
terminals are proportional to the strength of the magnetic field and the
frequency (HZ) of the resulted voltage waveform depends on the speed of
rotation and the number of poles.
Hint: Frequency means the number of complete cycles of the
generated voltage per second and it measures in HZ.
At the end we should know that when the current flow throw the
generator armature ,it faces the resistance and inductive reactance of the
armature windings which called the internal resistance and after that the
current will flow to feed our loads ,Consequently lamps will light , motor will
rotate, factories will work and commercial building will be illuminated
…….. Indeed we cannot live without electricity, it consider the artery of
the life.
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