Transcript High-Voltage Transmission

Objective 16.01
• Define Common electrical terms
Electrical Terms
• Electricity: a source of energy that can be
converted to light, heat, or power
– A movement of electrons caused by electrical
pressure or voltage
– The amount of energy produced depends on
the number of electrons in motion
• Electricity is produced from generators
that are run by water, steam, or internal
combustion engines
Hydroelectric
• Water used as a
•
source of power to
turn generators
Examples: Fontana
Dam
– Niagra Falls Dam
– Kinzua Dam
TVA
• TVA: Tennessee Valley Authority
• May 18, 1933 TVA Act was signed by
President Franklin D. Roosevelt
• 1942: 12 hydroelectric dams where being
built in the area employing 28,000 people.
TVA
High-Voltage Transmission
Power Plant
Large Industrial User
Step-Up Substation
Transmission
Substation
Residential
Electrical
Delivery
Local
Substation
Farms
Schools
Small
Businesses
Homes
The Path of Electricity
Power Plant
Inside a generating plant,
water is heated to
steam by nuclear reaction
or fuels such as natural
gas,
oil and coal. Steam turns
turbines and magnets
to produce electric
energy. Water at
hydroelectric dams also
can
turn turbines.
The Path of Electricity
Step-Up Substation
Substation transformers
at generating plants
increase electric energy’s
pressure (voltage) so it can
move long distances over
power lines that transmit
up to
500,000 volts.
The Path of Electricity
High-Voltage
Transmission
• High-voltage transmission
lines carry electric energy over
long distances.
• Insulators on
the towers prevent energy
from going into the ground
or on the structure.
The Path of Electricity
Transmission
Substation
Transformers at highvoltage
substations reduce voltage
to
a lower level (34,500 to
115,000 volts) suitable for
local use.
The Path of Electricity
Large Industrial User
Some large industries need high voltage power (2,300 to 4,000
volts) to run heavy machinery.
They usually have a small substation outside the facility.
The Path of Electricity
Transmission
Substation
Transformers in mediumvoltage neighborhood
substations reduce the
voltage even more
to be distributed to
homes and businesses.
Your electric cooperative
operates several of these
substations.
The Path of Electricity
Distribution Lines
Your cooperative’s distribution lines carry 7,200 to 13,200 volts of
power. These poles may also hold telephone and cable TV lines. In
some areas, distribution lines are in underground conduits.
The Path of Electricity
Transformers on Poles
Electric power passes through
transformers on poles to reduce voltage to
levels for use inside farms, schools, small
businesses and homes (120/240 volts).
Electrical Terms
• Ampere: the rate of flow of electricity
• Volt: the measurement of electrical
pressure
• Watt: the measurement of electrical
power
• Kilowatt: 1000 watts
• Circuit Breaker: protects circuits form
overload of current by tripping to break or
open the circuit
Electrical Terms
• Fuse: protects circuits form overload by
melting a metal strip in the fuse
• Conductors: materials such as copper,
aluminum, or water that will carry or
conduct electricity
• Insulators: materials such as rubber and
plastics that will not conduct electricity
Electrical Terms
• Hot wire: a current-carrying conductor
under electrical pressure
• Neutral wire: a current-carrying conductor
NOT under electrical pressure (has volts)
• Ground wire: a conducting wire that
transmits current to the earth to minimize
the danger of electrical shock
The Path of Electricity
Area enlarged
Residential
Electrical Delivery