A presentation about generation, transmission, and conversion of Electricity By: Ali Reda Ali Science school, Cairo University 20 Dec. 2016

1. Generation,
Transmission, And
Conversion of
Electricity
Introduction to electrical circuits
By: Ali Reda Ali

2. Electricity, The important thing in the 21th century -
that I think-.
One a day, do you think about
no electricity?
Simply, I would not present this
show to you!
TVs, Computers, Metro, Cars, ...
Etc. The first thing that they
want to work is the electricity.
The evolution of our life because
of electricity.

3. We want every day to a huge quantity of
energy, electricity is almost energy to want
and we can convert it –simply- to another
form of energy.
But, How do we get the
electricity?

4. We can get the electricity energy
from
• Coal (The most unfriendly-enviro resource)
• Earth (From hot rocks deep inside the Earth)
• Water (Generating energy by waves)
• Sun (Using solar cells)
• Wind (The amount of energy depends on the amount of
wind, using an electricity generator on top of a tall
tower).
4

5. There are two types of energy
resources
5

6. Energy Resources
6

7. First: Generation of
Electricity
The fundamental principles of
electricity generation were discovered
in 1830s by Michael Faraday.
This method is still
used today:
electricity is
generated by the
movement of a loop
of wire, or disc of copper
between the poles of a magnet.

8. First: Generation of Electricity Cont.

9. First: Generation of Electricity Cont.
Almost all electrical power on Earth is generated with a
turbine, driven by wind, water, steam or burning gas. The
turbine drives a generator. There are many different
methods of developing mechanical energy, including heat
engines, hydro, wind and tidal power. Most electric
generation is driven by heat engines. modern steam
turbine (invented by Sir Charles Parsons in 1884) currently
generates about 80% of the electric power in the world
using a variety of heat sources

10. Second: Transmission of
Electricity
Electricity is generated at power plants and
moves through a complex network, or grid, of
electricity substations, power lines, and
distribution transformers before it reaches
consumers. By default, there is a lose in energy
generated because of the high length of wires
and the temperature in the sands.

11. Second: Transmission of Electricity
Cont.
According to Faraday's Law, since
the same magnetic flux passes
through both the primary and
secondary windings in an ideal
transformer, a voltage is induced
in each winding, in the secondary
winding case, in the primary
winding case. The primary EMF is
sometimes termed counter EMF.
This is in accordance with Lenz's
law, which states that induction of
EMF always opposes development
of any such change in magnetic
field.

12. Second: Transmission of Electricity
Cont.
Real transformer energy losses
are dominated by winding
resistance joule and core losses.
Transformers' efficiency tends to
improve with increasing
transformer capacity. The
efficiency of typical distribution
transformers is between about 98
and 99 percent.

13. Finally: Conversion of
Electricity
AC current is generated by turbines, but your
mobile want to DC current to charge.
DC current is generated by semiconductors solar
cells, but your fridge or TV wants to AC current
to work.
How we can convert between them?

14. AC VS DC!
Alternating current
describes the flow of
charge that changes
direction periodically.
As a result, the voltage
level also reverses
along with the current.
AC is used to deliver
power to houses, office
buildings, etc.

15. AC VS DC Cont.
Direct current is a bit
easier to understand
than alternating
current. Rather than
oscillating back and
forth, DC provides a
constant voltage or
current.

16. A- AC Input To DC Output
The task of turning AC into DC is called rectification, and the electronic
circuit that does the job is called a rectifier. The most common way to
convert alternating current into direct current is to use one or more
diodes.
A charger 5V circuit

17. • A bridge rectifier overcomes this limitation by using four
diodes instead of two. The diodes are arranged in a
diamond pattern so that, on each half phase of the AC
sine wave, two of the diodes pass the current to the
positive and negative sides of the output, and the other
two diodes block current.
A- AC Input To DC Output Cont.

18. B- DC Input To AC Output
Semiconductors solar
cells are source of DC,
but we want to use
this energy to run AC
devices.
Inverter, is an
electronic device or
circuitry that changes
DC to (AC).

19. It is a power amplifier driven by an astable multivibrator. However, rectifier
filtering capacitors required are considerably smaller at the higher operating
frequency. The two transistor should be mounted on an adequately sized
heatsink. The transformer should be rated according to the amount of
output power required allowing for conversion efficiency of approximately
60%
B- DC Input To AC Output Cont.

20. Thanks
Ali Reda Ali
Tuesday, December 20, 2016