An adaptive localization method for real-time security analysis

A new adaptive localization method for fast real-time AC security analysis using a modification of the fast decoupled power flow algorithm is presented. The method exploits the property that the impact of most contingencies encountered in security analysis is limited to localized regions of the network. Although it is intended mainly for contingency evaluation, the method is also suitable for contingency screening. On each iteration, a localized region is adaptively identified as the set of buses whose mismatches exceed specified tolerances. The sparse mismatch vectors for these buses are then efficiently processed by sparse vector methods to solve for the significant bus voltage magnitude and angle corrections required for security analysis. Reactive power limits on generators are enforced and all other appropriate automatic control adjustments are performed for the localized solutions. Test results on two practical systems show CPU time improvements over full AC solutions ranging from 3:1 to 5:1