problem with FOC current controller

Hi everyone,

I am working on BLDC motor FOC control. I am developing firmware based on VESC firmware. But i am having some problem with Vq value that keeps on increasing.

I have recorded the following waveforms.

ia,ib,ic values as shown in the figure-1.(When motor is running at 40 rpm).

https://drive.google.com/file/d/1tHZQX-4irIUovVOT7dZfZIXkkkD7rye2/view?u...

Vapha(RED), Vbeta(BLUE) as shown in figure-2. (When motor is running at 20 rpm)

https://drive.google.com/file/d/1nGROfBY0DE5zQnSCAferMDmkdyzBAkAG/view?u...

Vq(RED) and Vd(BLUE) as shown in figure-3. (when motor is running at 40 rpm)

https://drive.google.com/file/d/1VqiC9VGNrUGG4F_yXuBwxFx6Xy86VAtB/view?u...

Motor rotates but it starts rotating slowly, like initially it starts with a very low RPM that its movement cannot be perceived but the change in encoder signal can be observed on CRO. Vq signal is continuously increasing with very low rate.

I don't know why motor starts very slowly and takes significant time to get an rpm?

is it a FOC PID tuning problem or something related to FOC?.

I have done some more experiment to better explain the problem that can be seen here.

https://electronics.stackexchange.com/questions/621631/problem-with-foc-...

Please help.

Thanks.