Transmission expansion planning with AC model based on generalized Benders decomposition

This paper proposes a method for solving transmission expansion planning (TEP) problems with application of an AC model. The TEP will be solved by the proposed three-stage procedure. Firstly, a DC model is employed with an application of Benders decomposition to find initial cuts to be used in the next stage. Secondly, the problem is decomposed into investment and operation problems, for which an AC model will be used with initial cuts obtained from the first stage. An optimal plan will be obtained at the end of the second stage. Finally, reactive power optimization is performed. The proposed method is illustrated with a well-known 6-bus Garver system, and then tested with IEEE 24-bus and 75-bus northeastern Thailand systems to demonstrate the advantage of the TEP based on the AC model.

► This paper proposes a transmission expansion planning problem using an AC model.
► Problem is formulated in a decomposed structure.
► Advantage of the AC model over the DC model is clearly shown.
► Benefit of loss saving in the proposed method is shown compared with others.