help with third harmonics

Discussion in 'Homework Help' started by Kapitan, Aug 24, 2010.

  1. Kapitan

    Thread Starter New Member

    Aug 22, 2010
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    i am a student of electrical engineering. i am unable to understand the source of third harmonics current in a 3-phase transformer and how it is harmful. PLEASE HELP!!!!!!!!!!!
     
  2. Curleeee

    New Member

    Aug 12, 2010
    7
    0
    Kapitan,
    There can be third harmonic distortion of sine waveforms even in single phase transformers. It is caused by magnetic saturation of the iron core. Gets worse as the transformer power rating is approached.
    The sinusoid essentially has its peaks flattened. If you sketch a sinusoid, then a smaller wave at three times the frequency and add them, you will see the effect.

    It can be a harmful condition because of the additional heat dissipated in the transformer. A less harmful effect may be additional noise produced by motors when driven by distorted sinusoids.
     
    Last edited: Aug 24, 2010
  3. Kapitan

    Thread Starter New Member

    Aug 22, 2010
    2
    0
    thanks a bunch curleeeee...............
     
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