Optimum HVDC-Transmission Expansion Planning - A New Formulation

A new flexible mixed-integer formulation is presented in this paper for solving the single-stage transmission expansion planning problem. In this paper, only HVdc-transmission networks are considered as possible reinforcements to existing HVac-transmission systems. Unlike earlier ac-planning formulations using sensitivity analysis together with integer programming, this formulation uses the exact dc-equations and does not require the existence of sensitivity coefficients. And since dc-networks are not likely to exist in actual ac power systems, such sensitivity coefficients will not be available in most cases. The optimal configuration minimizes an annually amortized cost function including the investment cost for equipment additions and the operating cost in terms of real-power transmission losses. An example has been incorporated to illustrate the potentials of this new planning formulation.