Transcript Generation and Distribution of electrical energy

Generation and Distribution of
electrical energy
Grade 8
Energy generation
Electric generation
• The electricity generation sequence
involves taking charge from the Earth,
doing work on it to give it energy
(expressed in terms of voltage),
transporting the energy via a distribution
system, using the energy, and dumping
the spent charge back to the Earth. The
Earth acts as a charge
reservoir and reference potential for the
energy transfer process.
Generation and Distribution of electrical
energy diagram
Electric generation
• While this picture of the Earth as the
reservoir of charge from which charge is
taken and to which charge is returned after
the energy is used is the "big picture" of
the large generation and distribution
system, it may not be applied too literally
in the local situation. You cannot depend
on a "ground" connection to the Earth to
be sufficient as the path by which charge
returns to the Earth.
Coal used to proproduce electrical
energy
Electric generation
• In particular, just a connection to a
grounding rod is not a sufficiently low
resistance path to provide shock
protection by quickly carrying charge to
the Earth in the case of a short circuit to
ground. For electrical safety, the ground
wire must be "bonded" back to the neutral
of the supply transformer to force the
tripping of the breaker in a ground fault
situation.
Distribution of electrical energy
Electric distribution
• The electric energy obtained in the electric
generation process must be transported to
the end user by electric conductors without
large resistive power losses in the
distribution process. A key part of the
strategy for doing so involves
using transformers to increase the voltage
to hundreds of thousands of volts to
minimize loss to heat in the transmission
wires.
Electric distribution
• The three high voltage conductors shown
on the utility pole at right indicate that the
power distribution is "three-phase", with
each conductor 120 degrees in phase
away from each of the others. If each
section of the large insulators can
withstand a working voltage of 10,000
volts, these conductors may be operating
at something like 150,000 volts.
How electrical energy get to our homes
Video web site
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http://www.youtube.com/watch?v=fQNQKkvGQL0- (Anatomy of a Distribution System)
•
http://www.youtube.com/watch?v=pXasvq1ivnw (How Power Gets to Your Home )
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http://www.youtube.com/watch?v=-ZBNNcczmDM (The Journey of Electrical Energy )
•
http://www.youtube.com/watch?v=gggqvitMDuY (Electrical Power Generation )
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http://www.youtube.com/results?search_query=how+is+electricity+generated+animation&oq
=how+is+electricity++&gs_l=youtube.1.2.0l10.2364.47320.0.53031.24.19.1.4.5.0.1561.9733.
2j1j2j5j2j3j1j2j1.19.0...0.0...1ac.1.cFN0WgSFxVw ( how is electricity generated animation)
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http://www.youtube.com/watch?v=20Vb6hlLQSg (Energy 101: Electricity Generation )
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http://www.youtube.com/watch?v=e_CcrgKLyzc (How do you make electricity from coal animated video)
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