  Direct methods can provide rapid screening of the dynamical security of large
numbers fault and contingency scenarios by avoiding extensive time simulation.
We introduce a computationally-efficient direct method based on optimization
that leverages efficient cutting plane techniques. The method considers both
unstable equilibrium points and the effects of additional relay tripping on
dynamical security\cite{01SH}. Similar to other direct methods, our approach
yields conservative results for dynamical security, however, the optimization
formulation potentially lends itself to the inclusion of additional constraints
to reduce this conservatism.
