B-G431B-ESC1 / - Speed error

[LeeYoung]

Hello. I'm using B-G431B-ESC1 to operate drone motor

The operation was successful using FOC, but from 28,000 RPM and above,

it changes to - speed as seen on the Pilot screen. 

(When the rpm becomes negative, speed control becomes impossible.)

In fact, using betaflight, I have seen it go up to 45,000 rpm.

Any idea how I can change the minus speed or what I need to change??

[GMA]

Hello @LeeYoung,

Refer to this post.
If an internal electrical speed overflow occurs (depending on the maximum speed and the number of pole pairs of the motor), modify the firmware to use hertz (Hz) instead of tenths of hertz (0.1 Hz), as described in the post.

[LeeYoung]

Thank you for your reply.

After making the changes you shared, it worked, but at RPMs above 28K,

the value still changes to negative and becomes uncontrollable.

Is there any other way??

  

[GMA]

Hello @LeeYoung,

Could you provide the electrical characteristics of your motor?
In addition, a previous user resolved this issue by using the STO-CORDIC sensorless observer. Did you try this approach?