Optimal Routing and Design of Radial Medium Voltage Power Distribution Networks Considering Cables Short Circuit Withstand-Capacity

Cables short circuit withstand-capacity plays a crucial role in medium voltage distribution system design. For a given short circuit level at substation, fault current at any point in a radial distribution system depends on the location with respect to the substation, distributed generation as well as size and length of upstream cable sections. This paper addresses optimal routing, cable sizing, distributed generation allocation and sizing of radial medium voltage power distribution network considering cables short circuit withstand capacity. Both synchronous-based and inverter-based distributed generators are considered. Complete formulation of cables short circuit constraints (SCCs) is introduced in mixed-integer linear programming (MILP) form. A Benders-decomposition-based approach is used to solve the problem by considering short circuit at each system bus in a separate slave feasibility problem. Combinatorial cuts are proposed to exclude infeasible solutions in each iteration by investigating upstream routes, cable sizes and distributed generation. The proposed optimization framework and solution algorithm are applied on 54 bus, 84 bus and 138 bus systems. The results revealed potential saving in investment, maintenance and losses costs compared to upgrading method. Also the proposed solution algorithm showed great saving in the number of added constraints to the original problem.