Distribution line downsizing based on a set of non-dominated solutions for a network reconfiguration problem of an electric distribution system with many objectives

摘要

To provide electric power supply to consumers even in abnormal situations, the equipment used in electric distribution systems, including distribution lines, have sufficient capacity margins. Maintenance and/or replacement of these lines involving network reconfigurations are routinely performed. Since the monetary costs of equipment investments are significant, downsizing the equipment is important from the standpoint of cost savings. In this paper, we propose a method to downsize distribution lines while maintaining the feasibility of the network reconfigurations. The proposed method consists of three steps. First, (1) sets of non-dominated solutions approximating the Pareto fronts of the network reconfiguration problems are found by a many-objective evolutionary algorithm. Second, (2) the distribution system operator specifies the preferred solutions among the sets found in (1). Finally, (3) a set of downsized lines is chosen from among the set of lines under the condition that the specified reconfiguration procedures remain feasible even after downsizing the lines. A computational experiment using a large-scale distribution system model demonstrates that the proposed method successfully identifies within a practical computational time those distribution lines that provide possibilities for downsizing and their downsized capacities.