Critical transmission cut-sets identification within power grids

It is crucial to quickly and accurately identify the critical transmission cut-sets to ensure the secure operation of power grids. This paper proposes a method for identifying the critical transmission cut-sets which form major flowgates from generators to loads within the power grid. Specially, the active power transaction between generator and load buses is proposed to derive the critical transmission cut-sets with the improved PageRank Algorithm. Firstly, the nodal criticality of buses is quantified on the basis of improved PageRank algorithm where the Google matrix and the relinking vector are modified. Furthermore, a new topology for identifying critical transmission cut-sets is constructed according to the nodal criticality of buses and the network transformation. The transmission cut-sets identification problem is thus converted into shortest paths searching in the new topology. The searching area is determined based on the active power transaction between generator and load buses. Finally, the set of transmission lines forming the critical transmission cut-sets, with highest criticalities between generator and load buses, are identified by searching the shortest paths. Numerical examples show that the proposed method can efficiently and accurately identify the critical transmission cut-sets within power grids, and provide guidance for system monitoring and protection.