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.

HVPM SENSOR LESS SPEED CONTROL NOT WORKING

I have purchased HVMTRPFCKIT and running my servo motor rated 91V 1.6A and 0.64 Nm torque using HVPM enhanced sensorless project. Up to Build level 6 all the thing works properly. In Build 7 also if I don't put any load motor woks fine. If I put load first and then start motor, Motor stops showing high current protection though load is very small. If I gradually increase load step by step, at particular point is stops making noise but over current condition doesn't occurs.  I tried to tune PI parameters but it doesn't worked. Making PI more and more active and fast cause problem of over current at one point. Everything works fine with load for current loop with LSW=1. Please help me for converting this to speed control loop with lsw=2. 

  • Hi Sameer,

    We have contacted our expert on this. Unfortunately, he is not available at this time. He will respond as soon as he is available.
  • Sameer,
    Speed loop tuning for PMSM sensor-less control is one of most challenging task for motor control engineer, some-time it can take weeks of efforts to get PI coefficient right. The intention is not to discourage you but to let you know about complexity of the problem. That’s why I would strongly recommend you to look into our Insta-spin FOC and Insta-spin Motion solution. Insta-spin motion is exact solution to your problem because it has feature to auto-tune Speed loop.
    However if you would still like to pursue classical enhanced SMO solution, below are suggestions based on my experience for any new development:
    1. You must have high ppr encoder fix to your motor, and first thing is to get successfully run encoder base foc (including speed lop) with all load condition. This will give you base PI coefficient for d-q current + speed PI loop.
    2. Second important thing is to fine tune SMO gain to get right rotor position Theta and speed feedback, as close to sensor based solution, as explained in build level 3.
    3. Tune the current loop with maximum and minimum values of Iq, (which will eventually generated by speed loop). Make sure system is stable within this range of Iq with sensor-less Theta.
    4. Once you achieve above, adding Speed loop should not be as issue. You will slightly adjust the gain of sensor base PI coefficient to get right functioning.
    Best RegardsMilan-Motor Applicaiton Team
  • Milan,
    Thanks for your reply. I checked various ki and kp loop gains but under load its not working at all, Can you please help me in detail procedure of PI coefficient calculation and tuning procedure?My motor is 91V 2A permanent magnet. Also I  can not build level 8 and 9 as default error to contact TI sells. Please suggest good solution for my purpose.  

  • Sameer,

    This particular code has been used in different applications without such issues.

    Your motor may need a higher speed during transition of lsw from 1 to 2. Try increasing/decreasing the sliding mode gain Kslide at transition. If you can run the motor fine in lsw=1, the speed loop PI may not contribute to any such issues. While at lsw=1, you can verify if esmo1.Theta and speed3.EstimatedSpeed are correct and free of glitches and good to use.

    Hope it helps.

    rgds,

    ramesh