A new option Auto Save also saves the current project(s) has been added to the Auto Save preferences panel. When you enable this option, Auto Save creates an archived copy of one or more current projects, but also saves the current working project. This setting is off by default.
Auto saved versions have a suffix with the date and time it was saved (yy-mm-dd-hh-mm-ss) appended to the project name (for example, ProjectName-2018-08-31_09-53-41.prproj).
When an auto save occurs, Premiere Pro creates a new backup project file and adds it to the auto-save folder as an emergency project backup. This file is always the latest saved version of that project.
For more information on auto-save preferences, see Set Auto Save preferences.