The interconnection of renewable energy sources with distribution systems is attracting increasing interest
because these renewable sources are inexhaustible and nonpolluting. Wind and photovoltaic are
among the most mature of these energy sources, and their penetration continues to increase. In this
paper a method based on GA (genetic algorithm) is presented to investigate the distribution system
reconfiguration problem taking into consideration the effect of load variation and the stochastic power
generation of renewable DG (distributed generators units). The presented method determines the annual
distribution network reconfiguration scheme considering switching operation costs in order to minimize
annual energy losses by determining the optimal configuration for each season of the year. The uncertainties
related to DG power and varying load are considered by the creation of a probabilistic
generation-load model that combines all possible operating conditions of the renewable DG units with
the probability of their occurrence, followed by the incorporation of this model into the reconfiguration
problem. The constraints include the voltage limits, the line current limits, the radial topology, and
feeding of all loads. In order to evaluate the effectiveness of the proposed method, both balanced and
unbalanced distribution systems are used as case studies.