Induction motor in state space

Discussion in 'Math' started by kokkie_d, Nov 24, 2010.

  1. kokkie_d

    Thread Starter Active Member

    Jan 12, 2009

    From literature the induction motor has been well described in state space, see attachment- Induction Motor-01.jpg:

    This equation describes the induction motor with a rotating rotor.

    To describe a rotating stator as a consequence of the 3 phase supplied power, the following equation can be used, see attachment - induction motor - rotorary frame -02.jpg:

    Now, my question is the following:

    I have a little difficulty understanding the second equation, the one showing the inclusion of the rotorary stator frame.
    Because when I simulate a power supply (through the use of 3 combining 3 sine waves set 120 degrees apart)
    <br />
3 phase = A*(sin(\omega t+\theta) + sin(\omega t+\theta+2\pi/3) + sin(\omega t+\theta - 2\pi/3))<br />
    then I can control the amplitude by adjusting A and the speed by adjusting f within \omega and any start angle by \theta.

    This should give me control of the motor by adjusting its power supply and I would not need the rotorary frame reference?

    On the other hand if I use the rotorary frame reference I only need to control the amplitude of the signal and the speed within the stator, right?

    Are my last statements true?