Identification of External System Equivalents for Steady-State Security Assessment

A methodology is developed for obtaining network equivalents of external systems for on-line security assessement purposes. The problem is formulated either as a constrained or unconstrained optimization problem. By proper selection of the topology of the equivalent network, sparsity effects are retained while the accuracy of outage analysis using the equivalent model is maintained within predetermined bounds. This methodology is foreseen as the basis for testing and updating network equivalents for on-line applications.