Download How electricity is taken to the home

The
discovery
of
electricity
How electricity is taken to the
1
The discovery of electricity fact
sheets reviewed and updated with
the assistance of STAV Publishing
home
Electricity cannot be stored easily and so the
generators at brown coal fired power stations
work 24 hours a day to produce electricity.
From the power station, a complicated <network>
of overhead lines and underground cables brings
the power to your home.
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friendly
Conductors and insulators
A wire is a convenient means of conducting electricity because
electricity flows easily through some metals. It will not readily flow
through substances, such as rubber, porcelain, glass, plastics or
dry air. To confine electricity to a wire it is necessary that the wire
be surrounded by a substance such as rubber, porcelain, or air.
Materials through which electricity flows easily are called conductors
and non-conductors are materials through which it will not flow.
Insulators are non-conductors which prevent electricity escaping
from the conductors.
CONDUCTORS
INSULATORS
PLASTIC INSULATOR
WIRE CONDUCTOR
2
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3
Voltage and current
Before the electricity supply system can be explained in further
detail, it is necessary to understand the meaning of the terms
“voltage” and “current’. Voltage is the term used for electrical
pressure and may be compared with pressure under which water
flows through a pipe. Current is the term used for the rate of flow of
electricity in a conductor and corresponds to the rate of flow of water
in a pipe.
The amount of electrical power which can be transmitted (carried)
depends upon the voltage (pressure) and the current (rate of flow).
By using high pressure electricity, we can transmit a large amount of
electrical power through comparatively thin wires in the same way as a
lot of water power can be passed at high pressure through small pipes.
Pressure is always in a water
pipe. The current of water flows
only when the tap is turned on.
Power stations throughout the State are interconnected by a
6,359 kilometre network of high voltage transmission lines. If these
lines were operated at the normal household pressure (230 volts),
enormous wires many metres in diameter would be required in
place of the conductors now used. Long distance transmission of
electricity is impossible without a high voltage.
PRESSURE
IS ALWAYS
BETWEEN WIRES
CURRENT OF
ELECTRICITY
FLOWS ONLY
WHEN THE
CIRCUIT IS
COMPLETED BY
CLOSING THE
SWITCH
A SMALL PIPE
CARRYING WATER
AT HIGH PRESSURE
WILL CONVEY AS
MUCH WATER AS
A LARGE PIPE AT
LOW PRESSURE
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From power station to your home
Electricity is generated in power stations at voltages of between
6kV and 20kV (6,000 volts and 20,000 volts). This sounds high,
but the pressure of the electricity is increased even further through
transformers at the power stations before it commences its journey
along transmission lines. These transformers are able to “step-up”
(increase) the voltage to 220,000 volts and even 500,000 volts, which
is 917 and 2,083 times respectively greater than the household supply.
This high voltage helps electricity travel along the wires better:
The extra high voltage transmission system is connected to the
main centres in the State. Major switching centres and substations
transform the very high voltages down to 66,000 volts which is used
for the sub-transmission system around the metropolitan area and
some country districts. Zone substations have further step-down
transformers which lower the voltage to 22,000 or 11,000. Electricity
at this voltage (pressure) can then be transmitted on smaller, lighter
power poles.
The supply is finally reduced to 230 volts by pole or small ground level
transformers, and so to homes, factories and offices.
Most houses receive their power supplies from overhead mains
(wires) because it is cheaper than underground cables but in some
areas people are prepared to pay more for undergrounding. In
Victoria developers of new housing estates are required to put new
infrastructure underground. This improves the appearance of the
houses and neighbourhood.
4
NEMMCO manages the interconnected transmission network from
two control centres in different states. Each of Victoria’s transmission
and distribution businesses has their own control centres to direct the
operation of their networks.
Electricity is supplied directly, to more than 2.3 million customers.
print
friendly
How electricity is taken to the home
Further investigations
How electricity is taken to the home
<http://en.wikipedia.org>
Voltage: <http://en.wikipedia.org/wiki/Volt>
Direct current: <http://en.wikipedia.org/wiki/Direct_current>
Alternating current: <http://en.wikipedia.org/wiki/Alternating_current>
Conductor: <http://en.wikipedia.org/wiki/Conductor>
Insulator: <http://en.wikipedia.org/wiki/Insulator>
5
Conductors and insulators:
<http://hyperphysics.phy-astr.gsu.edu/hbase/electric/conins.html>
<http://www.regentsprep.org/Regents/physics/phys03/ainsvscon/default.htm>
<http://www.glenbrook.k12.il.us/gbssci/phys/Class/estatics/u8l1d.html>
<http://www.thetech.org/exhibits/online/topics/13a_flash.html>
print
friendly
How electricity is taken to the
Electricity cannot be stored easily and
so the generators at brown coal fired
power stations work 24 hours a day
to produce electricity. From the power
station, a complicated <network>
of overhead lines and underground
cables brings the power to your home.
Conductors and insulators
A wire is a convenient means of conducting
electricity because electricity flows easily
through some metals. It will not readily
flow through substances, such as rubber,
porcelain, glass, plastics or dry air. To
confine electricity to a wire it is necessary
that the wire be surrounded by a substance
such as rubber, porcelain, or air.
Materials through which electricity flows
easily are called conductors and nonconductors are materials through which it
will not flow. Insulators are non-conductors
which prevent electricity escaping from the
conductors.
Voltage and current
Before the electricity supply system can
be explained in further detail, it is necessary
to understand the meaning of the terms
“voltage” and “current’. Voltage is the term
used for electrical pressure and may be
compared with pressure under which water
flows through a pipe. Current is the term
used for the rate of flow of electricity in a
conductor and corresponds to the rate of
flow of water in a pipe.
The amount of electrical power which can
be transmitted (carried) depends upon the
voltage (pressure) and the current (rate of
flow). By using high pressure electricity, we
can transmit a large amount of electrical
power through comparatively thin wires in
the same way as a lot of water power can be
passed at high pressure through small pipes.
Power stations throughout the State
are interconnected by a 6,359 kilometre
network of high voltage transmission lines.
If these lines were operated at the normal
household pressure (230 volts), enormous
wires many metres in diameter would
be required in place of the conductors
now used. Long distance transmission
of electricity is impossible without a high
voltage.
From power station
to your home
Electricity is generated in power stations
at voltages of between 6kV and 20kV
(6,000 volts and 20,000 volts). This sounds
high, but the pressure of the electricity is
increased even further through transformers
at the power stations before it commences
its journey along transmission lines. These
transformers are able to “step-up” (increase)
the voltage to 220,000 volts and even
500,000 volts, which is 917 and 2,083 times
respectively greater than the household
supply. This high voltage helps electricity
travel along the wires better:
The extra high voltage transmission
system is connected to the main centres
in the State. Major switching centres and
substations transform the very high voltages
down to 66,000 volts which is used for
the sub-transmission system around
the metropolitan area and some country
districts. Zone substations have further
step-down transformers which lower the
voltage to 22,000 or 11,000. Electricity
at this voltage (pressure) can then be
transmitted on smaller, lighter power poles.
home
developers of new housing estates
are required to put new infrastructure
underground. This improves the appearance
of the houses and neighbourhood.
NEMMCO manages the interconnected
transmission network from two control
centres in different states. Each of Victoria’s
transmission and distribution businesses
has their own control centres to direct the
operation of their networks.
Electricity is supplied directly, to more than
2.3 million customers.
Further investigations
How electricity is taken to the home
<http://en.wikipedia.org>
Voltage: <http://en.wikipedia.org/wiki/Volt>
Direct current: <http://en.wikipedia.org/
wiki/Direct_current>
Alternating current: <http://en.wikipedia.
org/wiki/Alternating_current>
Conductor: <http://en.wikipedia.org/wiki/
Conductor>
Insulator: <http://en.wikipedia.org/wiki/
Insulator>
Conductors and insulators:
<http://hyperphysics.phy-astr.gsu.edu/
hbase/electric/conins.html>
<http://www.regentsprep.org/Regents/
physics/phys03/ainsvscon/default.htm>
<http://www.glenbrook.k12.il.us/gbssci/
phys/Class/estatics/u8l1d.html>
<http://www.thetech.org/exhibits/online/
topics/13a_flash.html>
The supply is finally reduced to 230 volts by
pole or small ground level transformers, and
so to homes, factories and offices.
Most houses receive their power supplies
from overhead mains (wires) because it
is cheaper than underground cables but
in some areas people are prepared to
pay more for undergrounding. In Victoria
The discovery of electricity fact
sheets reviewed and updated with
the assistance of STAV Publishing