STSPIN32G4. sensorless tuning

[JLC]

Hello,

For our battery-powered smoke extraction fans, we want to develop a brushless motor driver 1.5KW.

For this new development we use the reference STSPIN32G4.

I use a custom EVSPIN32G4 circuit board with a 4 pole pairs brushless motor equipped with hall sensors.

I use MC workbench 6.2.1 for the application.

We have a product who work fine with the software configuration in hall sensors.

Today we want to migrate this application (fan application) in sensorless mode.

 

in sensorless mode, I am encountering some difficulties:

About 1 in 20 starts goes wrong and ends up with a speed fedback error, the other 19 starts happen normally. I would like to have advice on finding the right setting knowing that I have already followed your recommendations in your various supports. I have tested : different value for the regulator settings, different value for Pll ki and G2 value.

 

Here is a description of the malfunction: Each time the speed feedback error appears, the propeller of my fan is staled from the first phase of startup as if the initial positioning was incorrectly carried out. When start-up goes normally, I notice that sometimes the fan propeller moves slightly in the opposite direction of operation before starting. Is this normal?

 

You will find all my configuration for motor control workbench 6.2.1 in the attachment.

 

Thanks for your help.

Julien.

[JLC]

Hello community,

Here is some information that allows me to correctly adjust the start of my sensorless application :

My motor has a fairly high moment of inertia, this seems to be a fairly common problem.
The areas of work that allowed me to resolve my problem are as follows :
- I increased the duration of the alignment phase, from 500ms to 1500ms.
- I also reduced the start-up speed threshold, which allowed me to reduce the duration of the startup phases.

It is still possible to reduce the start-up time, to do this it would be necessary to lower the threshold.

Hope this can help the community.

Julien.