A Novel Slow Coherency Based Graph Theoretic Islanding Strategy

Slow coherency analysis is used to effectively determine the slowly coherent generator groups among weak connections for any given power system. A novel graphic theoretic method is proposed in this paper to simplify a large scale power system into a smaller network without losing optimal solutions. A multi-level recursive bisection graph partition method is employed to partition the reduced network into desired sub-networks with minimum generation-load imbalance. The relevant simplification rules and partitioning procedure are presented. The strategy is tested on the pre-cascading August 14, 2003 scenario for the eastern interconnection. The simulation results show that the proposed islanding strategy is effective.