Author(s)

Sun Zhiyuan, Liu Mosi, Liu Peng

Corresponding Author

Sun Zhiyuan

ABSTRACT

Critical lines in the power grid have an important role in the large-scale cascading failures. In order to improve the accuracy of the critical line identification and to prevent the blackout, a new method for identifying the critical line based on the line proportion is proposed. The proposed method defines a degree of flow transfer connection, weighted lines and then based on the absolute value of the change of the load rate of the tie line caused by the change of the active power of a certain line; the line proportion of each line is calculated and compared. Last, the simulation results show that the proposed method can quantitatively characterize the influence of power flow transfer on the load rate of tie lines due to the disconnection caused by a DC or a AC line fault. It has important significance to identify the weak lines in the power grid effectively and accurately, to determine their roles in the evolution process of self-organized criticality in AC/DC hybrid power grid, and it is of great significance prevent the cascading failure system to the critical state of evolution.

KEYWORDS

critical line, power flow transfer, AC/DC hybrid power grid, cascading failures