What is the most likely cause of the motor noise?

[DF_MC]

Hello Everybody,

Here are the software and boards in this case:

1. MC workbench 6.3.2
2.STEVAL-IHM039V1/STEVAL-CTM009V1

I am using an I-PMSM motor with the ST development boards (STEVAL-IHM039V1 / STEVAL-CTM009V1). In open-loop mode, the motor spins smoothly and quietly. However, when I switch to normal mode—which uses the Hall speed sensors and ICS current sensors—two issues arise:

1. The motor consistently produces a high-frequency noise.

2. At low speeds (e.g., 500 RPM), there is a noticeable lack of torque; the motor cannot sustain rotation when I manually apply light resistance by hand.

Could you please help identify the main cause of this problem?

Thank you for your help.