Is anyone able to drive a BLDC motor at low speeds? anything below 6 RPM?

[msingh]

I am using the X-NUCLEO-IHM08M1 as a power board and NUCLEO-F303RE as a control board. Using an incremental encoder of 1024CPT I was able to drive the motor as slow as 6RPM, even after several attempts I was unable to achieve any lower speeds. When I request any lower speeds the motor stops and goes into the "lock rotor" meaning the motor stops rotating but still draws current.

Thanks In advance

Manpreet

[mscot.1]

Position control mode - AN5464 and set Duration to zero. It works.

[msingh]

Hi @mscot.1​ ,

Really appreciate your help. I will try this soon.

Kind Regards

Manpreet

[msingh]

Good morning mscot.1,

Thank you once again for your suggestion I have created a project using the AN5464 and the motor is able slower than 6RPM (I think) however I cannot use the "follow mode" as mentioned in the application note. When I set the duration to 0 it should start a continuous rotation if i keep updating the position however the rotor doesn't move at all. Is there any suggestion you have?

I would appreciate your help.

Kind Regards

Manpreet Singh

[mscot.1]

Sorry, I have not got anything more to offer; I followed the App Note and achieved the motor moving between 2 positions. Then I set the duration to zero and advanced the angle in a loop and it worked. That is as far as I went.

[msingh]

Hi,

would you be kind enough to share the "loop" you have please?

I am able to move between 2 position however I cannot achieve any continuous movement, below is the code I am using.

[msingh]

[msingh]

Actually I have identified the issue. THANK YOU VERY MUCH FOR YOUR HELP. MUCH APPRECIATED :)

Have a nice day.

Kind Regards

Manpreet Singh

[Imen.D]

Hello @msingh​ ,

Please, let us know how you solved your issue ?

Then, please select the post which is "Best Answer" or mark your post as answered the question.

Best Regards

Imen

[msingh · Accepted solution]

Hi @Imen DAHMEN​ ,

I used position control instead of speed control which allowed to rotate slower than 6RPM, then adjusted PIDs to eliminate overshoots and vibrations, then I just had a bad connection and the motor simply stopped rotating ( I thought it was a firmware issue but it wasn't as it stopped working with the previous version of firmware) .

PID tuning is really a big issue. Personally I do not reccomend the Motor profiler as it is not usefull at all, the parameters should be used from the motor datasheet and PID tuning should be done manually.