AC mains frequency

Discussion in 'General Electronics Chat' started by cssc, Oct 20, 2014.

  1. cssc

    Thread Starter New Member

    Oct 19, 2014
    26
    1
    why the AC mains frequency is usually only 50 or 60 Hz?
    why not any other frequencies..? some kHz or something.?
     
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  2. Papabravo

    Expert

    Feb 24, 2006
    10,180
    1,800
    From the wikipedia article at:

    http://en.wikipedia.org/wiki/Utility_frequency

    In the late 19th century, designers would pick a relatively high frequency for systems featuring transformers and arc lights, so as to economize on transformer materials, but would pick a lower frequency for systems with long transmission lines or feeding primarily motor loads or rotary converters for producing direct current. When large central generating stations became practical, the choice of frequency was made based on the nature of the intended load. Eventually improvements in machine design allowed a single frequency to be used both for lighting and motor loads. A unified system improved the economics of electricity production, since system load was more uniform during the course of a day.
     
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  3. cmartinez

    AAC Fanatic!

    Jan 17, 2007
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    It has to do with the way generators were designed in the first place. From a practical perspective, the number of windings and the rpms at which these generators ran converged in the frequencies that you're mentioning. But the complete story might be a little more complicated than that.
    Check this article, it provides some insight on the subject
     
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  4. alfacliff

    Well-Known Member

    Dec 13, 2013
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    428
    low frequencies cause lights to blink. at the time high frequency equipment had more loss and was harder to build. while there were high frequency alternators like 18 khz at 250 kw, those were only used for radio transmission. and the 50 or 60 hz makes it easy to figure out gear ratios for clocks.
     
  5. MaxHeadRoom

    Expert

    Jul 18, 2013
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    400Hz is used on aircraft in order to cut down the size on the magnetic devices and save weight.
    Max.
     
  6. wayneh

    Expert

    Sep 9, 2010
    12,156
    3,064
    For power transmission, I believe high frequency leads to higher losses and straight DC is being looked at for this very reason.
     
  7. JWHassler

    Member

    Sep 25, 2013
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