Improving the mathematical formulation of security-constrained generation capacity expansion planning using power transmission distribution factors and line outage distribution factors

This study proposes an efficient formulation for multi-stage DC-based security-constrained generation capacity expansion planning problem (GCEP) using power transmission distribution factors (PTDF) and line outage distribution factors (LODF). This paper compares the classical DC-based formulation with the PTDF&LODF-based formulation. Both formulations are applied to model the security criteria solving both pre- and post-contingency constraints simultaneously. For the proposed formulation, the pre- and post-contingency transmission network constraints have been modeled using only the power generation as decision variables. The main advantage of this formulation is the reduction of decision variables in the operation problem. Furthermore, the inclusion of security criteria in the optimization problem strengthens the generation investment plan. Authors have conducted several experiments with different electrical power systems in order to validate the better simulation time obtained by the proposed formulation. Results show that the proposed formulation, which requires fewer decision variables, and equality and inequality constraints than the classical DC formulation, reduces simulation time without sacrificing optimality. Overall, this methodology could be applied for solving medium- and large-scale power systems.