GUIDES & HOW TO'S
Where can i see if my VeloCloud device has lost power?
Why there isn't a specific event captured by Edge device losing power, I believe the event "EDGE_MGD_SHUTDOWN" would best represent or be expected in your event log.
I do have a request in with VMware to add a more specific event to capture Edge device losing power.
Please let me know if this information helps or if you need additional information regarding particular ticket/ event.