Cascade animation #1

The following pages depict the evolution of a simulated major cascading failure of the Eastern Interconnect, one of three large-scale transmission grids in the United States, with tens of thousands buses (nodes) and lines (arcs).  The cascade is initiated by disabling two high power flow lines. 

We evaluate a cascade according to three criteria:
We study two cases of the cascade.  In one case the cascade is uncontrolled, that is to say, no action is taken and the cascade is allowed to run its course. In the second case the cascade is governed by an affine, adaptive load-shedding control.  The control is constrained in two ways:
Background material is found in this report (a short version, here).   This work was previously funded by DOE grant DE-SC000267 (now funded by DTRA grant HDTRA1-13-1-0021).

The uncontrolled cascade becomes stable in the 34th round with a yield of approximately 78% and 4425 outaged lines. 
The control we consider in these pages is approximately optimal subject to the above constraints.  It sheds load in rounds 2 and 7 only; it achieves stability at the 19th round with a yield of approximately 75% and 2598 outaged lines.

In the pictures, outaged lines are shown in black.  The geometric layout of the grid was not obtained using actual coordinates (unavailable) but was instead computed using sfdp.

The cascade starts here.