Warning: Cannot modify header information - headers already sent by (output started at /home/content/70/7481070/html/appsrc/doyouknow.php:18) in /home/content/70/7481070/html/header.php on line 20

Warning: Cannot modify header information - headers already sent by (output started at /home/content/70/7481070/html/appsrc/doyouknow.php:18) in /home/content/70/7481070/html/header.php on line 21
Do You Know
Questions & Answers on General Knowledge.

Is DC power transmission possible?
You're right that DC (direct current) power transmission has some important advantages of AC (alternating current) power transmission. In alternating current power transmission, the current reverses directions many times per second and during each reversal there is very little power being transmitted. With its power surging up and down rhythmically, our AC power distribution system is wasting about half of its capacity. It's only using the full capacity of its transmission lines about half of each second. Direct current power, in contrast, doesn't reverse and can use the full capacity of the transmission lines all the time. DC power also avoids the phase issues that make the AC power grid so complicated and fragile. It's not enough to ensure that all of the generators on the AC grid are producing the correct amounts of electrical power; those generators also have to be synchronized properly or power will flow between the generators instead of to the customers. Keeping the AC power grid running smoothly is a tour-de-force effort that keeps lots of people up at night worrying about the details. With DC power, there is no synchronization problem and each generating plant can concentrate on making sure that their generators are producing the correct amounts of power at the correct voltages.>/p> >p>Lastly, alternating currents tend to flow on the outsides of conductors due to a self-interaction between the alternating current and its own electromagnetic fields. For 60-cycle AC, this "skin effect" is about 1 cm for copper and aluminum wires. That means that as the radius of a transmission line increases beyond about 1 cm, its current capacity stops increasing in proportion to the cross section of the wire and begins increasing in proportion to the surface area of the wire. For very thick wires, the interior metal is wasted as far as power delivery is concerned. It's just added weight and cost. Since direct current has no skin effect, however, the entire conductor can be carry current and there is no wasted metal. That's a big plus for DC power distribution.>/p> >p>The great advantage of AC power transmission has always been that it can use transformers to convey power between electrical circuits. Transformers make it easy to move AC power from a medium-voltage generating circuit to an ultrahigh-voltage transmission line circuit to a medium-voltage city circuit to a low-voltage neighborhood circuit. DC power transmission can't use transformers directly because transformers need alternating currents to move power from circuit to circuit. But modern switching electronics has made it possible to convert electrical power from DC to AC and from AC to DC easily and efficiently. So it is now possible to move DC power between circuits by converting it temporarily into AC power, sending it through a transformer, and returning it to DC power. They can even use higher frequency AC currents and consequently smaller transformers to move that power between circuits. It's a big win on all ends. While I haven't followed the developments in this arena closely, I would not be surprised if DC power transmission started to take hold in the United State as we transition from fossil fuel power plants to renewable energy sources. Using those renewable sources effectively will require that we handle long distance transmission better than we do now and we'll have to develop lots of new transmission infrastructure. It might well be DC transmission.
--- >>>
More Questions:
  • How is the human body a living machine?
  • Why does food become soggy after heating in the microwave oven, particularly pastry?
  • What are the most famous architectural structures in Asia?
  • Did the Renaissance change music?
  • What were the first boats like?
  • How does a magnetron work?
  • What is heat energy used for?
  • Why are so many flowers brightly colored?
  • Do all fish have bones?
  • What is inertia?
  • Which countries of the world have not formally begun converting to the metric system?
  • Why is the bugle call at day’s end called “taps”?
  • What did the Chinese take to Japan?
  • What are the two substances in a Lava Lamp, and why do they react the way they do?
  • Who was Homer?
  • Without gravity in space, what would happen to the recoil if a gun were shot off?
  • Were microwaves invented for the microwave oven?
  • Why do we call money saved for a rainy day a “nest egg”?
  • What are the various things that happen during a volcanic eruption?
  • Do insects lay their eggs in a nest?
  • Which male sea creature keeps its young in a pouch?
  • I want to know what dB, BIAS, HX-Pro, Dolby A-B-C-S Noise Reduction, and 20-bit LAMBDA Super-Linear converter (from DENON) mean.
  • How bloody was the Civil War?
  • Can rays be dangerous?
  • What is the difference between a planet and a moon?
  • Amazing Nail Art Designs For Beginners With Styling Tips
  • Fastest Things Known To Man
  • Christmas Gifts Ideas
  • Benefits of Ginger
  • Valentine Day Cards
  • Fashion Designers of all time

  • Washington

    Renwick Gallery

    The Renwick Gallery is a branch of the Smithsonian American Art Museum, located in Washington, D.C., and focuses on American craft and decorative arts from the 19th to the 21st century.It is housed in a National Historic Landmark building that was begun in 1859 on Pennsylvania Avenue and originally housed the Corcoran Gallery of Art (now one block from the White House and across the street from the Old Executive Office Building).When it was built in 1859, it was known as the American Louvre.

    Chourishi Systems