[amluto]

Do you have a reference?

If I followed this right, the frequency goes up with load (which seems backwards). So a 50%-loaded grid will be at 60.05 Hz. A newly started inverter will try to output 60 Hz (and fail, since it is unable to single-handedly reduce the frequency). But it will surely end up with nonzero current.

Don’t real spinning synchronous machines work the other way? If they are overloaded, they spin slower, and if they are spinning a bit slower than the grid when connected, the grid will speed them up?