Motor stuttering at lower duty cycle %

Hi there,

I am facing several problems with VESC setting up with a large drone motor.

My team wanted to utilize VESC's FOC function to increase motor efficiency.

If you can share us any idea, that would help us tremendeusly.

Problem 1

When we attempt to start the motor with duty cycle below 35%, motor would not start.

Below 35%, It stutters for a few seconds, and stops.

The motor starts to rotate when we give duty cycle around 40%.

Motor seems to be running fine when we give it a low RPM.

The reference video is linked below. FYI, the language in the video is Korean.

https://photos.app.goo.gl/fyvKyDeS1panePcm8

30 Second Mark: Starting motor with 20% cycle

45 Second Mark: Starting motor with 30% cycle

1:10min Mark: Successful start with 40%cycle

Problem2

The current measurement on VESC tool does not match actual current measurement.

The reference video is linked below.

https://photos.app.goo.gl/siCcxNCHui5jJgW3A

1:30 min Mark: Monitor on the right shows around 18A, but VESC tool displays 53A measurement.

Problem3

Motor shuts off randomly. Maybe related to above problems

https://photos.app.goo.gl/siCcxNCHui5jJgW3A

2:25 min Mark: Motor shuts off by itself

The information of the motor and the detaction results are listed below.

The motor

238150 stator size, 100V, 40poles, previously worked with ESCs provided by the manufacturer.

The ESC

VESC 100V 250A

VESC Detection Result;

Motor current:161.52A

Motor R: 10.20mohm

Motor L : 15.47 uH

Motor Lq-Ld:10.44uH

Motor Flux Linkage: 7.94mWb