Why does my BLDC motor stop during acceleration?

[Dror Laor]

Posted on March 30, 2017 at 10:12

I'm currently evaluating STSPIN32F0 as a solution for BLDC polygon motor control & drive.

My EVB is STEVAL-SPIN3201.

The application is:

• 38V nominal
• 8A max @ acceleration
• 60 deg displaced hall sensors
• 2 pole pairs

My Motor configuration is

When probing for hall-sensors feedback I get:

Sensors 1-3 correspond to channels 1-3 

respectively.

b-emf was also measured:

My sensor configuration is

When measuring b-emf on UVW terminals I get

UVW correspond to channels 1-3 respectively.

When trying to speed ramp to 15,000 in 15,000 ms I get the following UVW drives:

Motor starts spining for approx. 10s and then stops.

MC Workbench displays the flowing data after motor is stopped:

My SystemDriveParams folder & MC Workbench project is attached as a .zip file.

No changes have been made in the source files except commenting out &sharpdefine EXAMPLE_POTENTIOMETER and &sharpdefine FIRMWARE_VERS ''STM32 FOC SDK\0Ver.4.4.2''

Any Ideas?

Thanks,

Dror

#polygon #stspin32f0 #bldc #hall-sensors

[Enrico Poli]

Posted on April 07, 2017 at 14:03

Hello Dror,

In your configuration file the PWM frequency is set to 16k and the execution rate is 2, as a consequence the 'bandwidth' of the FOC algorithm is 16k/2 --> 8 kHz. Not so fast.

Moreover you are using a motor with low inductance value, so and high PWM frequency is recommended in order to keep the current under control.

Please, try the attached setup with fPWM = 24k.

________________ Attachments : SDK43x-STEVAL-SPIN3201-sankyo_hall.stmcx.zip : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006Hyj1&d=%2Fa%2F0X0000000bBZ%2F5ilfsM7LkZMGlUfXoA23IQdteVy6BFkC4BSX0UZl4U0&asPdf=false

[Laurent Ca...]

The question has been moved from the "Motor Control Hardware" section to the "STM32 Motor Control" section (the question is about the STM32 MC SDK). 

Best regards