  Intentional controlled islanding (ICI) is a final resort for preventing a
cascading failure and catastrophic power system blackouts. This paper proposes
a controlled islanding algorithm that uses spectral clustering over multi-layer
graphs to find a suitable islanding solution. The multi-criteria objective
function used in this controlled islanding algorithm involves the correlation
coefficients between bus frequency components and minimal active and reactive
power flow disruption. Similar to the previous studies, the algorithm is
applied in two stages. In the first stage, groups of coherent buses are
identified with the help of modularity clustering using correlation
coefficients between bus frequency components. In the second stage, the ICI
solution with minimum active and reactive power flow disruption and satisfying
bus coherency is determined by grouping all nodes using spectral clustering on
the multi-layer graph. Simulation studies on the IEEE 39-bus test system
demonstrate the effectiveness of the method in determining an islanding
solution in real time while addressing the generator coherency problem.
