Transmission Expansion Planning Challenges in the Paraguayan Electrical Power System

In an electrical system, the transmission system is particularly a fundamental infrastructure as it plays an important role for the accessibility and development of the electrical market. In the present work, an optimal planning of the transmission expansion to the Paraguayan electrical system was carried out, minimizing the operation and investment costs. A reduced equivalent system of the Paraguayan electrical system at 500 kV was elaborated, in which certain candidate works of the Transmission Master Plan of the Paraguayan Electrical Market Administrator were analyzed, applying mathematical optimization methods, having represented the network by a DC model. The mixed integer nonlinear programming problem is solved by programming in GAMS. As a result, it was determined from a set of candidate circuits, which are necessary to build for a given time horizon, so that the operating restrictions are satisfied and the operation and investment costs together are the minimum to supply the future demand. It is demonstrated that the results provide valid technical support for the selection of 500 kV works to be prioritized, and that there are works that can be reconsidered as they do not provide a reduction in operating costs or in terms of energy not supplied. In addition, for the particular case studied, it was observed that a minimum investment can mean large reductions in the operating cost of the system