Designing electric distribution circuits for improved system reliability

The increased reliability requirements of the current and future electric distribution circuits has called for new approaches to distribution system planning. This paper presents a reliability-based approach to designing electric distribution circuits while using a minimum number of distribution lines or secondary branches. The designed circuit topology considers both network and customer reliability requirements. Network reliability indices quantify the service availability of the entire distribution circuit while customer reliability indices measure the reliability of the specific customer load. A graph theory based computationally efficient algorithm is proposed to solve the topology design problem. The proposed algorithm is applied to design circuit topologies for the zonal distribution system of a shipboard power system and for utility distribution networks. The analysis demonstrates that the proposed algorithm is efficient in designing reliable circuit topologies.