Load shedding in a power network under defined emergency conditions is considered. The problem of minimizing load curtailment under a given set of emergency conditions has been formulated as a problem of static optimization, subject to certain operational and equipment constraints. The network equations, in the most general case, are the well known AC Power Flow Equations. An initial feasible steady-state solution of the post-fault system is obtained, using the efficient BPA Power Flow Program. The optimization equations are developed for the case of emergency operation, satisfying the Kuhn and Tucker conditions. The significance of the dual variables, and their utilization in the iterative approach toward a near-optimum solution are discussed. A computational procedure, similar to the one used for reactive power optimization, is proposed. The application of the model for system studies and planning purposes is stressed. A simplified approach to the problem, where the reactive productions and demands are neglected, is also formulated. This special case may allow faster computation with not much loss of accuracy, therefore seems better suited for control applications. Simple numerical examples illustrate the practical significance of the dual variables. Computer results of a 26-node network example are presented for two emergency situations. Themore » loss of generation in an isolated system and the loss of a tie-line between two interconnected regional systems are considered, and the best allocation of the necessary load curtailment among the various customers is calculated for each case.« less