A Fast-Screening Method for N-1 Critical Faults of Guaranteed Power Grid

The guaranteed power grid ensures a reliable power supply for important users under extreme conditions. It minimizes the impact on power grid security and power supply and comprehensively improves the power supply guarantee ability of significant areas and users. A fast-screening method for N-1 critical faults of the guaranteed power grid is proposed based on the concentric relaxation principle. Firstly., N-1 faults scanning is carried out for the equipment and transmission lines to obtain the N-1 fault set. Based on the concentric relaxation principle, the association matrix of each fault with system equipment and transmission line is determined. Then, the critical weight matrix is obtained according to the capacity and voltage level of the generator critical analysis and the transformer and transmission line parameters whether participating in power grid analysis. Next, the critical degree of N-1 faults in the guaranteed power grid is evaluated and ranked. The critical fault sets are adjusted under specific application conditions. Finally, the validity of the proposed method is verified by the IEEE 9-bus system.