HAMMERing away at Automated PowerPivot Refresh
See below for an updated version of the VBA code that automates the refresh of PowerPivot models. Having spent the last week delving deeper into the process I've made a few changes.
The original code doesn't work if more than one PowerPivot model is opened; the new method uses a combination of DMV (tabular views of AS engine's metadata) Sessions and Object Activity (in particular looking for 'Permissions' issued to a workbook's sessions).