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Magnetising circuit parameters in a 3ph induction motor

  1. Dec 13, 2015 #1
    1. The problem statement, all variables and given/known data

    2. Relevant equations

    3. The attempt at a solution
    Stator Line voltage 220 164 112 88 42
    Stator Line Current 6.8 5.4 3.9 3.8 3.7
    Stator power 470 360 278 244 232

    By plotting a suitable graph from these results, determine the total of windage and friction losses, the no load magnetising current Io (assume no load current Io is magnetising losses) and the equivalent circuit magnetising circuit parameters Ro and Xo.

    I have plotted the graph and estimated that the losses for friction and windage is 220w. I am unsure as to how to calculate the magnetising current and therefore the values of Ro and Xo.

    I(ph) =I(line)/ROOT3 = 3.93A
    Vph =V(line)/ROOT3 = 127.02v
    Pph = P(line)/ROOT3 = 127.02w
    cos THETA = P/V*I = 75.5deg, Lag
    Ro = V/IcosTHETA =129.09Ohm
    Xo = V/IsinTHETA = 33.38Ohm

    Or do I replace the power value with Total losses-friction and winding losses which equals 250w

    Any help in the right direction would be ace.
    Last edited by a moderator: Jun 14, 2017
  2. jcsd
  3. Dec 18, 2015 #2
    Thanks for the post! This is an automated courtesy bump. Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?
  4. Jun 10, 2017 #3
    Hi justadaftspark, how did you work out the friction and windage losses. the lessons don't show me the equation.
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