Islanding the power grid on the transmission level: less connections for more security

Islanding is known as a management procedure of the power system that is= implemented at the distribution level to preserve sensible loads from outa= ges and to guarantee the continuity in electricity supply, when a high amou= nt of distributed generation occurs. In this paper we study islanding on th= e level of the transmission grid and shall show that it is a suitable measu= re to enhance energy security and grid resilience. We consider the German a= nd Italian transmission grids. We remove links either randomly to mimic ran= dom failure events, or according to a topological characteristic, their so-= called betweenness centrality, to mimic an intentional attack and test whet= her the resulting fragments are self-sustainable. We test this option via t= he tool of optimized DC power flow equations. When transmission lines are r= emoved according to their betweenness centrality, the resulting islands hav= e a higher chance of being dynamically self-sustainable than for a random r= emoval. Less connections may even increase the grid's stability. These fact= s should be taken into account in the design of future power grids.