Sensorless FOC - sudden motor rotation change

[RReic.2]

Hi Community

I'm using the following setup:

• MC Motor Control Workbench v6.0.0
• STM32 FW V1.5.0 (HAL)
• Power + Control Board: B-G431B-ESC1
• Observer + PLL (Sensorless)
• Motor 10 pole pair
• Mech. Speed 200rpm

The motor starts and ramps up to 200rpm.

It can now happen that when there is a load change, the rotor suddenly turns at full speed in the opposite direction. The speed is displayed in the Motor Pilot. In this case, however, the phase current looks distorted.

What can be the cause?

[Javier1]

This looks a lot like the set speed functions expect a signed variable, and youre passing an unsigned variable.

[RReic.2]

I just press the button on the board which starts the motor with MC_StartMotor1() and no further action. Then this seems to be a problem in the SDK ?

[Javier1]

Maybe , check this out https://wiki.st.com/stm32mcu/wiki/STM32StepByStep:STM32_Advance_MotorControl

[RReic.2]

...this doesn't happen with "CORDIC"