Contingency Assessment of Electric Power System by Calculation of Unequal Priority Factors for Static Severity Indices using Analytic Hierarchy Process

Contingency analysis of electric power system operation, is considered as the most vital concern of its security appraisal. Present days, on-line security assessment is carried out by contingency ranking, with the help of various computing techniques. One of the iterative methods is Newton Raphson power flow method for obtaining the magnitudes of different parameters. The intention of contingency ranking is to create a short list of possible potential threats quickly and rank them according to their severity in an accurate manner. In this paper a static security assessment based approach is presented for contingency ranking, incorporating analytic hierarchy process as an improvement to the conventional power flow based ranking techniques. The proposed method is employed to choose proper unequal priority factors for the weighted severity index. The usefulness of the technique has been verified on IEEE 14 bus system and the results are presented with a detailed comparison, with the help of Network Graphical Overlays for pre and post-contingent states of power system.