Planning and design of urban low-voltage DC grids.

• A planning framework for low-voltage direct-current grids is proposed. • (Meta-)Heuristic methods are suitable for structure-dependent grid planning. • Cable trench costs are similar for radial, ring and meshed grids. • Line lengths and total annuity grid costs increase with higher meshing degree. Accompanied by further cost degression and technological development in the field of power electronic devices and DC technology, low-voltage DC (LVDC) grids for public power supply gain practical relevance for the future grid design, promising a solution to the technical challenges in the course of energy transition and digitization. In this paper, a comprehensive planning framework for urban public power supply LVDC grids is presented. Based on an analysis of degrees of freedom in such systems including potential for power flow control, the structural design of LVDC grids is investigated by explicitly planning radial, ring and meshed structures applying heuristic and metaheuristic algorithms on georeferenced supply data. Key to accuracy of the developed line courses is the orientation to existing traffic routes, establishing additional practical significance of the proposed approach. Three optimized LVDC grids as result of the case study are compared in terms of technical and economic aspects. [ABSTRACT FROM AUTHOR]