Among the most frequent reasons for power outages is stability loss and/or cascade failures in power grids, leading to a decline in power system integrity. The load shedding systems are the ultimate protection measures against system-wide failures in the event of loss of frequency (automatic underfrequency load shedding) or voltage loss (automatic undervoltage load shedding). The complex structure of the power system (renewables, wind farms, gas generators, etc.), transmission grid functions and rapid technology progress (synchrophasors, InteliGrid, advanced communications systems, etc.) have forced us to revise the current approach to load-shedding protection, in particular the automatic underfrequency load shedding and take other measure, including the adoption of advanced operation algorithms and a system-wide approach. In light of imminent geomagnetic disturbances (GMD), which may result in a rise in reactive power consumption and possible power system stability loss, undervoltage load shedding seems to be among the most efficient protection measures.