Security-constrained unit commitment: Modeling, solutions and evaluations

Unit commitment has been widely studied in the last few decades due to its importance in power systems operation. To ensure the reliability and feasibility of the operational constraints of the transmission network, the system operator needs to solve this problem, considering the security constraints. In this problem, the total operational costs during each day are minimized while considering all operational constraints of the generation units and the transmission network under various contingencies. Solving this problem in large networks is associated with many challenges, such as solution time and accuracy. From the perspective of the optimization literature, it is a high-dimensional non-convex problem. Different methods have been presented to solve the security-constrained unit commitment (SCUC). This paper presents a comprehensive and practical overview of the SCUC as a critical decision-making problem to determine optimal power generation schedules in the power system by investigating the most critical studies on this topic and providing a detailed classification of both modeling and problem-solving approaches for the existing real electricity markets. It also outlines the existing research challenges in this field by implementing test benchmarks on different types of SCUC problems and provides deep and novel insights. First, the various models available for this problem are summarized. Then, the different methods proposed to solve this problem are explained based on their characteristics and application scopes, are comprehensively categorized, and the corresponding solution methods are discussed. Finally, various methods are evaluated and compared through numerical case studies on benchmark formulations, and the potential future research directions in this field are proposed.