Power outage prediction by Hz-monitoring??

[danskeren]

Is the mains frequency of 60 Hz nominal a reliable health sign for the power grid? If so is then a viable solution preventing power outages by letting loads automatically disconnect from the grid, if the mains frequency drops below a certain limit? Or is it also necessary to keep an eye on the voltage? How low a mains frequency should still be accepted as an ok level? One could also measure the frequency-change over time (df/dt) if that would be more accurate.
This stuff is surely basic knowledge for any power engineer, but being "only" a computer engineer I am completely blank on this subject. Appreciate inputs –THX.

 

[dpc]

You're correct - on a power grid the frequency is a powerful indicator of the health of the system. Load-shedding schemes to prevent power system collapse are generally frequency-based. The frequency variation depends on the size and capacity of the power system. For a large interconnected grid, the frequency should be virtually constant, and a variation of 0.1 Hz would be a significant event. Load shedding would generally start automatically at 59.8 or 59.7 (on a 60 Hz system). For an isolated power system in Alaska, frequency is much less stable.

Do a web search on "load shedding" and you find a lot information.