• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Subscribers 81 subscribers
  • Views 635 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Values in per-unit in Dual Motor Control Kit Project

Carlos Camacho
Prodigy 200 points
Other Parts Discussed in Thread: CONTROLSUITE

Hi,

I'm working with Dual Motor Control Kit. Specifically, I am using the TI-designed project called 2xPM Motors.pjt. In this project, we modify the variable rotor speed and the voltages on the axes d and q. Specifically, the units of these variables are in per-unit, which I think are the normalized units. But then, what values ​​are in reality these units? What real value is a rotor speed of 1 per-unit?


Thanks in advance and sorry for my English.

 

Carlos

  • 0
    TI__Guru 57255 points

    Carlos,

    To answer your question directly, the max base frequency is max RPM Speed (SpeedRef) is defined to be 3000 RPM.  The units of SpeedRef are in per-unit as you mention. 

    In 2xPM_Sensorless.c, you can see that speed1.BaseRpm = 120*(BASE_FREQ/POLES), where BASE_FREQ and POLES are defined in 2xPM_Sensorless-Settings.h

    Take a look at the "Sensorless FOC of 2xPM.pdf" guide inside controlSUITE for much more information.


    Thanks,
    Brett

  • 0 in reply to Brett Larimore
    Prodigy 200 points

    First of all, thanks for the information.

    First question: then, 3000 rpm is the maximum motor speed?

    On the other hand, the BASE_FREQ is 200 Hz, and when I set up the motor speed to SpeedRef = 0.25, I've seen on the oscilloscope that the frequency of the intensities of the motor phases is 50 Hz, which corresponds to 200 Hz * SpeedRef. The argument is correct?

    Besides, if I configure SpeedRef = 0.25 and the maximum speed is 3000 rpm, I have to see that the motor speed is 750 rpm. Is that correct? I have no sensor to measure the motor speed, but looking at the motor shaft I think the speed is less than 750 rpm. Is this possible?

    Thanks in advance,

    Carlos

  • 0 in reply to Carlos Camacho
    Prodigy 200 points

    hello again,

    someone can resolve me any question?


    Thanks in advance,

    Carlos