3 Phase Voltage Help

Discussion in 'Homework Help' started by dmarullo3, Mar 26, 2013.

  1. dmarullo3

    Thread Starter New Member

    Mar 26, 2013
    2
    0
    Looking for some help with a hw problem. Having some trouble with AC phase relationships. In this problem im having trouble determining the phase sequence. I think i can get the angle from the frequency the three voltages are at. Help would be greatly appreciated. Ive attached an image of the problem.
     
  2. Paulo540

    Member

    Nov 23, 2009
    188
    0
    If Vb -> Vc -> Va, you can always reconfigure it to be a b c. Might make it easier.

    Also, it might help to note where the zeros cross on the chart instead of the peaks.

    I assume you are able to do the RMS and leg voltage calcs at this point. ?
     
  3. dmarullo3

    Thread Starter New Member

    Mar 26, 2013
    2
    0
    yes i have the RMS voltages, i know the between the three voltages they are 120 deg apart for the phase voltages and the line voltages are the same only separated by 30 deg.
     
  4. panic mode

    Senior Member

    Oct 10, 2011
    1,318
    304
    there are only two sequences - abc and bac
    since this is periodic, it repeats over and over so abc sequence looks like
    abcabcabcabcabc...

    you can see inside it 'bca' so this is 'forward' sequence

    if you swap any two phases, you get bac:
    bacbacbacbacbac...

    btw. 'bac' is similar to *back* (or reverse) sequence
     
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