中文摘要：

电力系统存在的少数关键线路在导致系统大规模连锁故障发生的过程中起关键作用，因此快速识别电力网络中关键的输电线路，特别是连锁故障过程中系统的关键线路，对有效实施过负荷连锁跳闸控制策略，预防电力系统大面积停电有着重要的意义。大停电事故一般伴随着线路有功潮流的大规模转移，针对此特征，提出潮流转移度指标，基于电力系统静态安全域分析的思想建立关键线路评估模型，提出一种电力系统连锁故障过程中关键线路的辨识方法。结合IEEE 30节点标准算例系统，利用OPA大停电模型构造了某次连锁故障过程，仿真验证了所提辨识方法的正确性。

英文摘要：

There exist a small number of critical lines in power system that play key roles in the process of the power system large-scale cascading failure, therefore, in order to implement control strategy effectively in overload cascading trips and to prevent large-scale blackout, it is significant to identify critical lines in the power system rapidly, especially when the system is in a cascading failure state. According to the characteristic that blackouts usually associate with the large-scale active power flow transferring, the flow transferring index was proposed as vulnerability index. Based on the idea of steady-state security region analysis of the power system, a critical lines assessment model was established and an algorithm was given to identify the critical lines in the process of cascading failure. According to the IEEE 30 standard example system, this paper constructed a simulation process of a cascading failure by using the OPA blackout model, and validated the correctness of the proposed identification method through simulation.