How the noise of brushless motors is generated

Brushless motors produce noise:

The first situation may be the commutation angle of the brushless motor itself. You should carefully check the commutation program of the motor. If the motor commutation angle is incorrect, it will also cause noise;

The second situation may be that the electrical angle of the brushless motor participating in commutation lags behind the mechanical angle for too long, resulting in fluctuations in the current in the motor, which naturally produces noise;

The third situation is that there is an internal problem with the brushless motor itself, and its coil has been offset or even damaged, causing noise.

Source: Xinda Motor