Power Grid-Oriented Cascading Failure Vulnerability Identifying Method Based on Wireless Sensors

Figure 2

The definition of -shell. Removing all the nodes with degree 1 and repeating this step until there are no nodes with degree 1 in the grid. Then, define their value of -shell as 1 (), which is the outer circle in the figure. Next, continue to remove the node with a degree of 2. As described above, the -shell value of the removed nodes is defined as 2 (), which is circle 2. Similarly, the -shell values of all points are obtained.