A two-phase method based on OBDD for searching for splitting strategies of large-scale power systems

System splitting problem, also known as controlled system separation problem, is to determine proper splitting points to split the entire interconnected transmission network into islands of load with matched generation when islanding operation of system is unavoidable. It is very difficult because of combinatorial explosion of searching space with the size of power network increasing. This paper proposes a two-phase method to find proper splitting strategies in real time by introducing the graph-model of system splitting problem. The method can narrow down the strategy space by highly efficient OBDD-based algorithm in the first phase and give all proper splitting strategies by power-flow calculation in the second phase. Simulation results on IEEE 30-bus test network shows that this method can quickly (in several seconds) give all proper splitting strategies guaranteeing synchronization, power balance and satisfaction to capacity constraints of transmission lines and other facilities in each island.