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.

为了即使在异常情况下也能为消费者提供电源，配电系统中使用的设备（包括配电线）具有足够的容量裕量。定期执行这些涉及网络重新配置的线路的维护和/或更换。由于设备投资的金钱成本很高，因此从节省成本的角度来看，缩小设备的尺寸非常重要。在本文中，我们提出了一种在保持网络重新配置可行性的同时减小配电线路尺寸的方法。所提出的方法包括三个步骤。首先，通过多目标进化算法找到（1）组近似网络重构问题的Pareto前沿的非控制解。第二，（2）分配系统运营商在（1）中找到的集合中指定首选解决方案。最后，在指定的重新配置过程即使在缩小线尺寸后仍然可行的情况下，从这组线中选择（3）一组缩小的线。使用大规模配电系统模型的计算实验表明，所提出的方法在实际计算时间内成功地识别了那些为缩小规模和缩小规模提供可能性的配电线路。