Transmission Expansion Planning with Linearized AC Load Flow by Special Ordered Set Method

Abstract

This paper presents a model for a transmission expansion planning (TEP) problem in which both active and reactive power as well as voltage magnitude of buses are considered through linearized alternating current (AC) load-flow constraints. The proposed approach uses the special ordered set of Type 2 (SOS2) to obtain the optimal global solution of the approximated linear model of TEP, which is indeed a mixed-integer linear programming (MILP) problem. This linear binary model can be effectively solved by existing off-the-shelf solvers using the branch and bound algorithm. The solution obtained is guaranteed to be globally optimal, whereas most mixed-integer nonlinear programming (MINLP) solvers could not guarantee an obtainable global optimal solution for nonconvex problems. The accuracy level of the solutions for the approximated linearized model can be easily controlled by adjusting specific parameters to suitable values. Results obtained through a simulation study show the effectiveness and applicability of the linear model presented. As numerous simulation studies show, the proposed methodology is reliable and robust.