Power transmission

Power Transmissions

& TransformersLauren Van Manen

How Does Electricity Get to Us?

• Our TV’s, computers, cell phones, Nintendo’s, refrigerators, the lights in our home…

• What’s going on to make the ‘ON’ switch work?

Production & Distribution!

• Electricity first must be produced at a power plant

• In order for us to receive this power, the power generated from the plant must be distributed.

• You may have noticed that almost everywhere you look, power lines are crisscrossed throughout; in our towns, cities, and entire county lines.

How is the energy produced?

• That energy made at the power plant isn’t made from nothing!

• Large generators spin to produce energy with a voltage of about 25,000 volts.

What’s a volt, anyway?

• Volt = the measurement of electromotive force in electricity.

• This is the electric force that “pushes” electrons around a circuit.

• Named after AlessandoVolta, an Italian physicstwho invented the first battery.

What happens next?• The voltage originally

produced at the generator of 25,000 volts isn’t quite enough, so there is another step:

• At the power plant, the electricity gets transported to a transformer that boosts, or “transforms,” the voltage up to 400,000 volts!

Why do we need more voltage?

• Think about it: We need our electricity to travel far distances at high speeds

• When electricity travels long distances, it is more efficient to be transferred at high voltages.

Is any electricity lost along the way?

• Transmission lines, or more casually referred to as power lines, are made of thick copper or aluminum cables

• Copper and aluminum have a low resistance

• The higher the resistance of a wire, the warmer it gets.

• This causes some electrical energy to get lost because it is transferred into heat energy.

Substations• After the voltage is

high enough, the power lines go into substations near high-traffic areas, such as businesses, factories, and homes.

• At these substations, transformers change high voltage electricity back to low voltage electricity.

Substations!

• Now, electricity in differing power levels from those substations can be used for daily life, such as for trains and traffic lights.

Is it home yet?

• Close to home, a small transformer mounted on a pole or in a utility box converts the power to even lower levels to be used in your home.

• Voltage is eventually reduced to 220 volts for things like your stove and clothing dryer.

• 110 Volts for lights, TV’s and other small appliances.

Underground Lines

• Due to modern technology, some new distribution lines are now underground.

• Not only are these not an eyesore, but they are protected from bad weather; such as high winds and ice storms.

How is electricity regulated?

• When electricity enters your home, it must pass through a meter.

• After being metered, the electricity goes through a fuse box into your home.

• The fuse box protects the house in case of problems.

Review!

• Electricity is generated at a power plant at 25,000 volts.

• Substations transform high voltages back to low voltages

• Electricity is transferred more efficiently at high voltages.

• The lower the resistance, the less energy lost.

• Voltage is a push force!

Works Cited:

• www.energyquest.ca.gov/story/chapter07.html

• Conceptual Physics textbook

• Google Images