• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Subscribers 81 subscribers
  • Views 743 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

TMDXIDDK379D: C2000 DesignDRIVE IDDK Kit issues

Dainius Narsutis57
Intellectual 495 points
Part Number: TMDXIDDK379D

Hi,

I have purchased the C2000 Dev Kit bundle for driving a 3 Phase motor (https://store.ti.com/TMDXIDDK379D-MTR-BNDL.aspx

Sensored Field Oriented Control of 3 - Phase Permanent Magnet Synchronous Motors using F2837x"  page 32 is guiding me to Run the motor and adjust the PI values for IdRef and IqRef. No matter what I am adjusting, nothing changes. Is there any information/videos of someone going through the kit step by step and getting it to run (Other than the manual I currently have). Could any one provide any additional guidance?

I have attached an image of the code running in LEVEL3 build. You can see that the EnabledFlag is 1, the MotorRun is 1 and I have set the IqRef to 0.05 (as per manual) and SpeedRef to 0.1 (I had it set to 0.3 as per manual).

The two graphs on the right side are pi_iq.Fbk and pi_id.Fbk respectively. I can change the pi_iq.Kp or Ki values but the graphs never change. In addition, with these default values, the graphs look a bit strange too.

Any advice would be greatly appreciated.

  • 0
    TI__Mastermind 27240 points
    When you change Kp and Ki values, it will only impact the transients of IdFbk and IqFbk, such as how slow or fast it responds to changes in Idref and Iqref. If the loops are already in steady state, its impact may not be visible.
  • 0 in reply to Ramesh Ramamoorthy
    Intellectual 495 points

    Ramesh, thank you for your response. I was trying to change the Ki, Kp values to evaluate how it affects the noise in the IdFbk and IqFbk. Is that not how it is suppose to work? I was hopping to see oscillations of the PI controllers as the Ki and Kp were being changed.

    Also, is there any reason why I should not just set the Build Level to BUILD5 and run the firmware.

  • 0 in reply to Dainius Narsutis57
    TI__Mastermind 27240 points
    What you are seeing is as per expectation. In general, the current loop is a first order system and is reasonably stable regardless of speed. When in steady state, the error is too close to zero that it may not show the effect of changes to PI constants.
    Due to digital control, the control delay can potentially lead to oscillatory behavior if the PI gains are quite erratic. Try different values for your education. Hope it answers.