Hierarchical network sectionalizing to improve present defense plans

This contribution benefits, as a typical example of black humor, of recent large-scale disservices experienced around the world in 2003. The authors were mainly involved, for obvious reasons, in the Italian one, dated September 28/sup th/. In such an incident, the present form of the local defense plan proved insufficient to rescue the electric grid from total collapse, since operating system protection schemes (SPS) did not provide adequate backup, that is additional corrective measures to cope with rapidly incoming cascading events.