A new mixed-integer methodology for optimal transmission expansion planning

This paper presents a new model and a solution methodology for optimal planning of high-voltage transmission network investments. The objective of this problem is to minimize capital costs needed for new network elements while meeting imposed operating constraints, and it is formulated via a linear mixed-integer model. Then, a new branch-and-bound methodology is proposed as the problem solution. The fundamental idea of this methodology is to reduce the number of discrete variables contained in the original set of unknowns. This reduction is achieved by using the decomposition principle and by developing a new separation of the region of feasible solutions. The proposed methodology was verified on several test examples, as well as on the real transmission network of the eastern part of former Yugoslavia.