Network reconfiguration in balanced and unbalanced distribution systems with variable load demand for loss reduction and service restoration

This paper presents a simple and efficient reconfiguration approach for balanced and unbalanced radial distribution networks with Distributed Generators. The proposed approach starts with meshed networks by closing all tie switches. A switching index is defined for reconfiguration using apparent power flow in lines. The radial configuration was restored by opening one switch in each loop subjected to system operational constraints. The switching index can be used for both loss reduction and service restoration during normal and emergency situations respectively. The time varying nature of loads through using daily load profiles was considered. The results concluded the effectiveness of: (i) fixed configuration compared to hourly reconfiguration in terms of energy losses and number of switching operations during normal operation; and (ii) building restoration plans with the consideration of load variation compared to plans based on pre-fault or peak load values. The proposed method has been tested on one balanced and one unbalanced systems.