Security-constrained Unit Commitment and Proposing the Probabilistic Model of Plants Inaccessibility in Emergency

This paper presents codification of multi-objective passive defense in unit commitment, aiming vulnerability reduction, feeding continuity, reliability enhancement, and increasing confronting potency. Consideration of multi-objective passive defense in the operation and planning of generation units is one of the important principles in dealing with military threats. In this work unit commitment in emergency condition has been executed by presenting a comprehensive multi-objective model constrained with different limitations and optimal strategies to determine the optimal level of generation and on/off state of each plant. The main targets of the presented planning technique are minimization of total production cost and maximization of voltage stability index by considering system reliability criterion. With respect to the different inaccessibility probability of each unit, a flexible and effective method based on the identification and weight assignment is proposed to calculate the reliability index. Due to multi-objective behavior of the presented method, multi-objective gravitational search algorithm is used to solve the problem. From a decision-making perspective, choosing a solution from among all the Pareto-optimal solutions obtained by MOGSA requires a high-level decision-making approach. Fuzzy decision-making based on Multiple Attribute technique is applied for finding the best compromise solution in this paper.