audible noise

KF Lam · ‎2016-11-30

Posted on November 30, 2016 at 16:44

Hi,

We have been using ST FOC SDK for more than a year. We make driver boards for HVAC motors with 1/2hp(375W)~1hp(750W). Our customer satisfies with the efficiency of our boards. However, the customer received a board from another vendor who uses another chip vendor's FOC solution last week. That board provides similar efficiency but is much more quiet than our boards. Our boards have audible noise while start up even with no load. The sound keeps noticeable loud until the load is increased the rated output. The sound is similar to the sound from a stepper motor controlled by a low end driver with wrong decay setting. We have tried reduce the current in start-up parameter but it doesn't help. Would you please give us some suggestions to eliminate this noise.

best regards,

KF Lam

KF Lam · ‎2016-12-01

Posted on December 01, 2016 at 16:39

update:

By reducing the Kp of Iq and Id from 2000 to below 200, the noise is almost eliminated. However, the motor becomes very unstable. The range of the motor speed can be +/-10% even if there is no load. Would you have any idea how to deal with this situation

best regards,

KF Lam

KF Lam · ‎2016-12-21

Posted on December 21, 2016 at 09:38

update 2:

Noise can be easily reduced (but not completely eliminated) by reducing the cut-off frequency of the 'Torque and flux regulators' to a value lower than 300~500rad/s. If we further reduce the cut-off frequency, the 'speed feedback' error will occur even if we reduce Observer C2 gain to 1/8 of the auto-generated value. We accept this as temporary solution and will study other MCU vendor's solution.

Laurent Ca... · ‎2021-06-15

The question has been moved from the "Motor Control Hardware" section to the "STM32 Motor Control" section (the question is about the STM32 MC SDK).

Best regards