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6-step speed fluctuation & current spikes

Nikolaj_TL
Associate III

I am facing issues while running a BLDC motor using the 6-step algorithm on the STEVAL-SPIN3201 board. The only modification I have made is to the Hall effect sensor low-pass filter to address noisy input signals.

I am encountering the following problems:

  1. Current spike on startup: 
    When starting the motor I apply a soft speed ramp, still I get this current spike on the phase current, which sometimes result in 'Over Current' Fault. What can be done to mitigate this? 
    scope_47.png
  2. Speed fluctuations: The motor speed fluctuates around the reference speed, resulting in uneven current draw (see "1500rpm_no_load.png"). I have tried adjusting the speed regulator tuning to be less aggressive, but this has not resolved the issue.

    1500rpm_no_load.png
  3. Current Spikes: Occasional current spikes in the phase currents trigger "Over Current" faults.

Do you have any suggestions on how to address these problems?


The .stwb6 project is included in the Info.zip file

10 REPLIES 10
cedric H
ST Employee

Hello @Nikolaj_TL ,

If you have issue with FOC algorithm, please open a new post describing your issue with all required information without considering that part of the information is already in this post. Could you mark the most suitable comment as "Accept as Solution" to close this thread.

Thanks

Cedric