Comparing deterministic and simulated annealing-based algorithms for minimum losses reconfiguration of large distribution systems

The paper deals with comparing different techniques to perform optimal reconfiguration of large MV distribution systems, with the objective of minimising the distribution system losses under a given set of constraints. The algorithms tested include three iterative improvement algorithms and two algorithms based on the simulated annealing method. The operating and structural constraints include minimum and maximum node voltages, maximum phase-earth fault current, maximum three-phase short-circuit current, maximum thermal current rating for each branch, detection of multiple cascade protections, maximum number of switch operations required to reach the final configuration starting from a reference configuration, and independence of supplies for customers with a second delivery point. The paper reflects the results of several experiences carried out by using specific tools, implemented by the authors, for the reconfiguration of large real urban distribution systems operating in a metropolitan area. Results are presented for a real urban distribution system with 240 nodes and 360 branches.