Transmission expansion planning: A review

Modern electric power systems consist of large-scale highly complex interconnected transmission systems and, thus, transmission expansion planning (TEP) has become a significant power system optimization problem in real time application. The TEP problem is a large scale, complex and nonlinear combinatorial problem of mixed integer nature where the numbers of candidate solutions are to be evaluated which increases exponentially with system size. The accurate solution of the TEP problem is essential in order to plan power system in both the economic and the efficient manner. Therefore, applied optimization methods should be sufficiently efficient while solving such kinds of problems. This paper presents the review of TEP problem from different aspects such as modeling, approaches for solving TEP, reliability, electricity market and tools for optimization. The review outcomes offer a widespread background of the planning issues and the corresponding solution approaches that may also lead to provide the future directions relating to this work.