Speed feedback fault when rev-up (B-G431B-ESC1 board and BR2804-1700 kV motor)

[AlexanderTHN]

Hello,

I am trying to get a BR2804-1700 kV motor running utilizing a B-G431B-ESC1 board. Till now I managed to get the motor starting to rev-up, but in the middle/at the end of the rev-up process I receive a "speed feedback"-error in the Motor Control Dashboard. Running the motor from Motor Profiler works without any problem.

I have already applied two fixes from the forum:

To fix ADC2 warning when generating Code, which did work https://community.st.com/s/question/0D53W00000JM31XSAT/adc2-warning-when-generating-project-for-bg431besc1

And I tried following fix, which had no effect eighter positive nor negative: https://community.st.com/s/question/0D53W00000HwV8RSAV/bg431besc1-motor-profiler-not-working-moderator-note-this-post-contains-now-a-bugfix-patch-on-provided-example

I have also tried to adapt the parameters as suggested in the STM32 PMSM FOC SDK

Frequently-asked questions (FAQ) document, e.g. decreasing the C2 gain, but it still does not work.

Is there any fix I missed?

If not, is there any way I can find the right parameter configuration without tens of hours of trial and error, which I have already tried (current parameters attached)?

When I run the motor using the Motor Profiler I get a PWM frequency of 30kHz(measured with oscilloscope), but when I try to use that frequency in my generated code I receive a "FOC-duration"-error and I have to change it to 16kHz. Why is there a difference?

I am currently using the STMCubeMX version 5.4.0 and MCSDK 5.4.4.

Many Thanks!

BR,

Alexander

[Laurent Ca...]

Dear @Alexander Köbler​ 

Sorry for the late answer.

Do you have still this problem to solve?

And just in case, if not, do not hesitate to share the final solution you found. Thanks by advance.

Best regards

Laurent Ca...

[AlexanderTHN · Accepted solution]

Hello Laurent,

Many Thanks for the answer anyway.

I was able to solve the described problem. Instead of decreasing the PWM frequency I had to increase the execution rate of the regulator, which automatically adapted the control parameters. I guess it would have also worked if I were able to adapt the parameters by myself in similar way.

BR,

Alexander

[Orso]

Hello Alexander,

I have similar problem. Standard speed regulator execution rate is 1.0ms. How much did you incrase it?

Thanks,

Orso

[AlexanderTHN]

Hello Orso,

I was talking about the execution rate of the flux and torque regulator.

I did set this execution rate from one to two PWM periods.

Whereas I have not adapted the execution rate of the speed regulator.

I hope that helps!

BR,

Alexander

[Orso]

Thank you Alexander,

I tryed to increase the execution rate from 1 to 2 for the flux and torque regulator, but then my motor fault at the beginning

of the startup phase.

The strange thing is that if I spin my motor without propeller I can reach 9000rpm before a "speed feedback" fault,

instead when spin the same motor with propeller I can only reach 7000rpm before a "speed feedback fault.

I don't understand why the same fault at different rpm.