As Windows stop codes go, DRIVER_POWER_STATE_FAILURE is fairly interesting. It indicates that a driver on your PC has fallen into an invalid or inconsistent power state. Thus, it usually occurs as PCs resume normal activity from some kind of Sleep or Hibernation state. Essentially, it crashes your PC and gives you a BSOD to avoid damage to the system or to data storage devices that might otherwise occur if the drivers and their associated devices were allowed to continue working.
Diagnosing DRIVER_POWER_STATE_FAILURE Causes
If you view the crash dump file from this BSOD, which you can do by installing and launching BlueScreenView, it will often identify a file by name as part of the crash data. By searching on the name, you can often associate it with some specific device inside (or, as is most typical for this error) plugged into your PC.

In fact, the most common devices that provoke a DRIVER_POWER_STATE_FAILURE error are USB drives (and other devices) of one kind or another: flash drives, drive docks, or external drive enclosures that may house SSDs, flash drives, or conventional hard disk drives.
The first step in dealing with DRIVER_POWER_STATE_FAILURE is to disconnect all external USB storage devices (keyboards and mice seldom, if ever, provoke this BSOD stop code). As the name of the error itself suggests, if a driver for any such device has been recently updated, it may also make sense to roll back (if possible) or to replace the current driver with an older, known working driver for your PC. If you don’t have a current backup of your PC, you should create one as the first step in the repair process. Then if anything goes amiss along the way, you can restore that backup to get back to where you started without too much muss, fuss, or stress.