Comment by cuu508

Thanks, anti-islanding protection must be a fascinating topic. You could look for voltage, frequency, phase anomalies but you also have to balance between being safe and having too many false positives. I'm not sure I'd want to be a line worker knowing there may be many inverters, from various manufacturers and with varying levels of quality, in every direction.

Perhaps a more robust solution would be for the power company to install remote-switchable circuit breakers at various places of the grid. Use some sort of wireless IoT protocol to listen for "on/off" signals and to report back "I'm now on / I'm now off!". Then the power company can disconnect parts of the network by themselves, without trusting that every inverter, generator and battery will do the right thing.