ABSTRACT A Distributed Generation ( DG ) is an electric power source connected to the distribution system directly or on the customer site . It presents a cleaner power production since various DG use renewable sources such as wind turbines ( WT ) and photovoltaics ( PV ) systems . The major features of DG are decreasing line losses , increasing efficiency , improving power quality , enhancing system reliability , and reducing fuel , operating , and maintenance costs . However , inappropriate selection of location and size of DG leads to greater losses and costs than without DG . Researches on optimal placement and sizing of DG in electrical iging a great