An Enhanced PTDF-Based Linear Formulation for Transmission Network Expansion Planning

The continuous growth of electricity demand and the global transition towards dependence on clean energy sources intensify the need for efficient and reliable longterm expansion planning of transmission networks. In this framework, transmission network expansion planning (TNEP) is a challenging problem involving nonlinear constraints and discrete decision variables, with inherent complexity often resulting in high computational costs, especially with more accurate models such as the disjunctive formulation for the DC model. This paper proposes an enhanced linear formulation for the TNEP problem that incorporates the power transfer distribution factor (PTDF) concept to reduce problem dimensionality and computational effort. The PTDF is a strategic tool to reduce the number of decision variables and constraints, enabling a more scalable optimization of the problem. Comparative results across several test systems confirm the effectiveness of the model and its scalability.