Need Help in "Harmonics in polyphase power system"

Discussion in 'Homework Help' started by mnada, Apr 28, 2012.

  1. mnada

    Thread Starter New Member

    Apr 5, 2012
    26
    0
    Dear All,
    I have a problem in understanding how the harmonic currents exist in a load with no corresponding harmonic voltages?
    The following figures with questions under explain what I mean
    [​IMG]

    This understood figure no issues about.

    [​IMG]

    In above figure, 2 question arise::confused:

    • How the line currents are missing the triplen harmonics
    • How the phase voltage is missing the other odd harmonics except the triplen


    [​IMG]


    In the above figure::eek:

    • How is the phase voltage missing all the harmonics while it's present in current.
    • Correct me if I am wrong: we can say that because triplen harmonics are in phase they cancel each other in the line cuerrent
    Thank you
     
  2. t_n_k

    AAC Fanatic!

    Mar 6, 2009
    5,448
    782
    Attached is my attempt at an explanation which unfortunately is rather wordy.
     
    mnada likes this.
  3. mnada

    Thread Starter New Member

    Apr 5, 2012
    26
    0
    I really appreciate your time and effort. Your response is quite helpful
    I fully agree with you that the second figure is missing the fundamental frequency voltage across the star connected load, that make perfect sense.
    Regards,
     
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