Improved contingency measures for operation and planning applications

Three new contingency measures are proposed and tested based on a large power system peak load base case. The Type II contingency measure is zero for all noncritical contingencies, has no misclassification or false alarm problems, and ranks contingencies according to their largest thermal limit violation. It should be used when operating conditions are known exactly. The Type III contingency measure has very small or zero contingency measure for noncritical contingencies, has no perceptible misclassification or false alarm problems, and appears to rank contingencies by their worst thermal limit violation. The Type III contingency measure is very useful for selecting contingencies where the precise operating conditions are unknown. A Type IV contingency measure sets branch weights to zero on all branches that do not experience thermal overloads for a set of contingencies. The Type IV contingency measure is useful for selecting single contingencies that when taken in combination could produce critical multiple contingencies