Research on Distribution Network Planning with Distributed Generation Considering Line Margin

The current planning for large-scale photovoltaic integration into the distribution network needs to balance electricity and transmission capacity, and the strategy of energy storage distribution network joint planning has emerged. Firstly, a line margin index is established as the evaluation basis for the transmission capacity of distribution network lines. Furthermore, a bi-level programming model was constructed that comprehensively considers economic costs and line transmission capacity. Collaborative planning was carried out for energy storage systems and distribution network lines, and the model was transformed from a two-layer model to a single-level model to solve the problem, reducing the difficulty of solving the model. Finally, a numerical example was compared between the collaborative planning strategy and other methods. From the simulation results, it can be seen that the proposed strategy not only has certain economic benefits in planning the expansion direction of the grid line and determining the energy storage capacity, but also has higher grid line margin and higher security in the proposed planning scheme.