Cascading failures in power systems propagate non-locally, making the control and mitigation of outages hard. In Part II of this paper, we continue the study of tree partitioning of transmission networks and characterize analytically line failure localizability. We show that a tree-partition region can be further decomposed into disjoint cells in which line failures will be contained. When a non-cut set of lines are tripped simultaneously, its impact is localized within each cell that contains a line outage. In contrast, when a bridge line that connects two tree-partition regions is tripped, its impact propagates globally across the network, affecting the power flows on all remaining lines. This characterization suggests that it is possible to improve system reliability by switching off certain transmission lines to create more, smaller cells, thus localizing line failures and reducing the risk of large-scale outages. We demonstrate using the IEEE 118-bus test system that switching off a negligible portion of lines allows the impact of line failures to be significantly more localized without substantial changes in line congestion.

中文翻译：

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电力系统级联故障的本地化和缓解，第二部分：本地化

电力系统中的级联故障会在非本地传播，这使得控制和缓解停电变得困难。在本文的第二部分，我们继续研究传输网络的树划分，并分析分析线路故障的可定位性。我们表明，树分区区域可以进一步分解为不相交的单元，其中将包含线路故障。当一组未切割的线路同时跳闸时，其影响会集中在包含线路中断的每个单元格内。相比之下，当连接两个树分区的桥接线路跳闸时，其影响会在整个网络中全球传播，影响所有剩余线路上的潮流。这种特性表明，可以通过关闭某些传输线来创建更多、更小的单元来提高系统可靠性，从而定位线路故障并降低大规模停电的风险。我们演示了使用 IEEE 118 总线测试系统，关闭可忽略的线路部分可以使线路故障的影响更加局部化，而不会显着改变线路拥塞。