excel from desktop, to power bi pubic, there should be a refresh button on the power bi public to able to force sync with the excel (desktop
Could you clarify what you mean by this? If you’re looking for a way to Refresh the dataset and reports from an Excel Workbook that you have connected to in the Power BI service (i.e. via OneDrive), this is already possible.
Both manual and scheduled refresh are supported. Check out this article: http://support.powerbi.com/knowledgebase/articles/474669-refresh-data