Research on vulnerable line identification based on PMU data and graph theory

Cascaded faults in complex power grids are prone to large-scale blackouts, and vulnerable transmission lines in cascading failures play an important role. Finding out these lines in power grid is very important to prevent accidents. The determination indicators of previous research methods are single. In this paper, a comprehensive analysis is carried out from two aspects of system operation structure and line power flow carrying capacity, and a vulnerable line identification method based on PMU data and graph theory is proposed. Firstly, a topology map of the power system is constructed in combination with the characteristics of PMU data visualization in actual power grid. Secondly, combined with power exchange efficiency and energy fluctuation probability, vulnerable lines of the grid are screened, and the effectiveness of the index is tested. Finally, the simulation experiment is carried out in the IEEE 30-bus system. Simulation results show that the proposed method can accurately identify weak transmission lines of the power grid.