Controlled Islanding for Enhancing Grid Resilience Against Power System Blackout

This paper proposes a transient stability constrained controlled islanding (TSC-CI) approach against cascading events in power systems. Using the wide area measurements, the proposed islanding algorithm is implemented regarding the actual dynamic conditions of the resulted islands. Since the main concern, right after the execution of controlled network splitting, is the transient stability of synchronous machines, a transient energy function is utilized for proper network partitioning. The proposed transient stability criterion is expressed as a function of the transfer impedance between each pair of generators in the resulted islands. Transfer impedance between each pair of coherent generators determines the direction of network splitting for transient stability improvement. A multi-objective function is then introduced to provide the transient stability with least possible power imbalance, as a resilience measure, over the created islands considering operational and structural constraints. Based on the wide-area measurements, a proper weighting procedure is utilized to prioritize the critical islands, avoiding the unnecessary power imbalance in favor of transient stability improvement. The proposed TSC-CI model is formulated as a mixed integer linear programming (MILP) multi-objective model and is solved using CPLEX in GAMS. The obtained results are compared with the conventional islanding scheme using the IEEE 118-bus system.