6PWM GD32F103 Doesn't turn smoothly

1

I’m trying 3PWM and 6PWM BLDCmotor openloop at GD32F103.
However, I have a problem and need your help.

・3PWM
It is spinning nicely. The motor rotates at approximately the same RPM as specified in the motor catalog.

・6PWM
The motor revs beautifully at lower RPM, but as the RPM rise, a noise-like sound that was not present in the 3PWM is mixed in. In addition, the duty setting was clearly larger than 3PWM, and as a result, I thought the efficiency was lower.

The 3PWM and 6PWM duty setting method uses SimpleFOC’s “SinePWM”.
The PWM waveform outputs HI around the center of the cycle based on the duty calculated by SinePWM, and then outputs HI in the opposite phase after a set dead time using the timer function.
When noise begins to mix at 6PWM, it can be improved by using the debugger to change duty and dead time in real time, but the noise sound is still more intense than at 3PWM.

I want to run motor 6PWM as smoothly as 3PWM, so I am trying to figure out the cause of this noise
sound but have not figured it out yet.

I’d like some food for thought, so do you have any idea what I should look out for when changing from 3PWM to 6PWM?
Do you have any idea for this situation?

2

HI,
in my case, reducing the driver.dead_zone = 0.0.5f helped.
But be aware, that it can go terribly wrong, if you set it too low and get shoot-through. Use a current limited PSU for testing.

PS: You can’t set the dead_zone via commander. You have to flash the controller everytime

3

Are you just using the barebones SimpleFOC library? Or are you using the GDF103 port that some people here wrote?

4

Thans for your advice.
I’ll try adjusting dead_zone.
I am using SA6288 gate driver which has internal dead time function.
So maybe I thiink it’s no probrem.

5

I am using SImpleFOC personally ported to GDF103.
I didn’t think anyone had already ported it to GDF103, so I didn’t look into it.
My apologies.

6

I have a GDF103 on one of my hoverboard controllers. It runs sFOC without any hiccups. Just had to select generic STM32F103 board in Arduino IDE.