Flexible Retrofit Planning for Distribution Networks in Urban High-density Load Areas

The increasing power demand and massive access of clean energy sources have put considerable pressure on the operation of distribution networks, especially in high-density load areas. DC distribution technology provides solutions for upgrading urban grids. In this context, this paper proposes a flexible retrofit planning model for distribution networks considering photovoltaic integration. The scheme coordinates the planning of DC lines and energy storage systems (ESSs) to mitigate local photovoltaic overflow and overload problems. The proposed model is transformed into a Mixed-Integer SecondOrder Cone Programming (MISOCP) formulation and validated through the case study based on a modified system in Zhuhai. The results demonstrate that the flexible retrofit scheme significantly enhances the economic efficiency and reliability of distribution networks.