"Rather than the grid syncing to the first spinning generator back up, would it be possible to have a defined time to sync to as defined by a GPS signal or the like."
Black starts (no power on local grid) are practiced by utilities that are willing to spend money on being prepared. Of course investors and customers do not want to spend money on things that might not happen so it's always a battle to do anything beyond minimum legal requirements. Most have little more than never fully tested procedures that fail to account for reality. For example a breaker that is programmed to not close in on a dead bus and takes hours to get to and override to force it close, and of course then opens when energised.
As for syncing that is rarely a problem, a greater problem is current and voltage.
If there is no power on the grid the transmission line has to be isolated from most or all loads. From the generators POV a long line or many de-energized loads looks like a dead short. Close on large loads (like a dead transmission line and transformers) and current will increase, voltage decrease, the generator will struggle to adjust and if procedure not followed it will slow down and open it's breaker to prevent damage. Which can still occur if you are foolish enough to bypass procedures or protections because the bosses want the power on right away.
Once a line is energized syncing on more units means bringing each new unit up to the require speed (sync) and voltage (phasing), closing it's breaker at which point it's speed is now locked into the systems speed. Of course that has to occur repeatedly until enough units are on line to start re-energizing larger parts of the grid, and then finally loads can be slowly added to bring the system back up.
Customers, homeowners, can help by reducing their own loads (open breakers). In some area's that is a requirement, in which case utility workers have to go house to house or transformer to transformer to remove loads before energizing and then house to house to add loads slowly.
Lots of fun and everybody wants it done immediately.
Biting the hand that feeds IT
