Motor accelerates too much when enabling on the fly startup

Hey everyone!

I was just exploring different features of the ST MCSDK and encountered the on-the-fly startup option dedicated to fan application.

Whenever I check this option, after the startup procedure, the motor accelerates to its nominal speed and then the firmware somehow takes control and run the closed loop to control the speed.

I tried to eliminate this behavior and changed a lot of parameters including speed PI coefficients and it didn't work

Is this behavior normal or am I missing something?

Has anyone had the same problem? Could you please guide me if you have any idea?

Thanks a lot!

Hey everyone,

to achieve this purpose, We need to check the Rev-UP algorithm in order to have a smooth transition between the open loop and the closed loop sensorless algorithm.(See what I have  attached)

Having done that, I observed that there was no peak in the speed after switching to the closed loop

Try this because it may help!

Regards.