Does semantic model update skip unchanged files?

Hi EmanuelParnaiba 

Have you looked into Incremetal refresh?

This lets you:
Indicate how far back to refresh

Provide an update field and only items with a new date will refresh

Using Premium have a live connection for some data, refresh import and finally stored non updating for the oldest.

Official page:

https://learn.microsoft.com/en-us/power-bi/connect-data/incremental-refresh-overview

Video guide (Guy in a Cube also made some great ones!):
https://www.youtube.com/watch?v=kH_mcS9Bv9E