I am designing a motor controller for a 26pole, 10,000rpm motor which gives me a fundamental frequency of ~2.2kHz.
I intend to operate the powerstage at 80kHz switching frequency and want to use the scaler to achieve this by using the recommendations on this and this post to achieve this. Would a control loop frequency of 26kHz with a 3x scaler be possible on the microcontroller in question? If not, will a 20kHz control frequency with a 4x scaler work? How would this second option behave at high speed given that it is less than 10x of the motor's fundamental frequency? Will it have an effect on stability, efficiency, or just not work at all?
Furthermore, I plan to use hall sensors to measure all 3 phase currents. What sensing bandwidth do I need in my sensors? Do I actually need a sensor with -3dB bandwidth of >2x80k = 160kHz? Since it is just measuring average phase current, would a 20-30kHz bandwidth sensor be sufficient?
Regards
Chai
