Motor parameter settings question to reduce of dithering

kissmucus · ‎2015-03-22

Posted on March 22, 2015 at 18:38

Hi!

I want to ask your help, and experience.

I got an unknown motor, but i measured the parameters by the STM32PMSMFOCSDK40_HandsOn v1.1.pdf documentation and by internet.

But something not correct yet.

My system is STM32F303VC controller, with 1 shunt resistor, and i use the embeded OAMP order to sensing current.

The motor start correctly (but at 1500 rpm vibrating and dithering, but at 1600 rpm starts run smooth) at the end of the spin up preiod start to contol the speed by the PID regulator.

In the run state the motor runs smooth, but late starts to to vibrate and dither more and more, at the end suddenly stopped.

My question:

I measured myself the all parameters of the motor, and maybe i made a mistake.

Where can i search the reason of dithering?

During the dithering use more current than normal.

the possible reasons maybe:

Incorect inductance, dead time length, or pid settings, or something else?

I hear all kind of suggestion :)

Thanks,

Gabor

Gigi · ‎2015-03-23

Posted on March 23, 2015 at 09:10

Ciao

Hard to say.

Try to attach some current waveforms to understand what happen.

You need to verify if the currents a are well regualted, then you have to take a look to the sensorless angle, and finally to the speed regualtion.

The DAC functionalities help a lot in this phase.

Ciao

Gigi