Integrated AC/DC transmission expansion planning model considering VSC-MTDC systems

Significant technological advances in the electric sector have led to complexity increase and created new challenges to transmission expansion planners. On the one hand, the increasing penetration of renewable energy sources impacts the entire network. On the other hand, DC systems have become a favorable and viable option to link some of these sources of energy to the consumer centers. Thus, new models of the network equipment must be incorporated to the Transmission Expansion Planning (TEP) model to take such changes into account in a more accurate way. This research work aims to include AC and multi-terminal DC transmission lines as candidates in the expansion planning process. The AC network model is used and shunt compensation is also taken into account to allow more flexibility to the expansion options. The TEP problem is solved using a combination of nonlinear programming and differential evolution (DE). The results obtained using a 9-bus test network and a modified IEEE-118 bus show the feasibility of this approach.