Data source and Incremental Refresh

Hey,

I am currently trying to set up my data source to Power Bi. I have data feeding into a shared drive, where my CSV files get updated at 1am. I also have historical data I will have to upload as well. So I have a file for historical data and another one with new data, which will have all updated data. I am looking to set up an incremental refresh and create some logic so only new data and any changes to old data gets refreshed. Would anyone be able to provide some advise on the best way to do this?