We address the problem of optimally re-routing the feeders of urban distribution network in Milano, Italy, which presents some peculiarities and significant design challenges. Milano has two separate medium-voltage (MV) distribution networks, previously operated by two different utilities, which grew up independently and incoordinately. This results in a system layout which is inefficient, redundant, and difficult to manage due to different operating procedures. The current utility UNARETI, which is in charge of the overall distribution system, aims at optimally integrating the two MV distribution networks and moving to a new specific layout that offers advantages from the perspectives of reliability and flexibility. We present a mixed-integer programming (MIP) approach for the design of a new network configuration satisfying the so-called 2-step ladder layout required by the planner. The model accounts for the main electrical constraints such as power flow equations, thermal limits of high-voltage (HV)/MV substation transformers, line thermal limits, and the maximum number of customers per feeder. Real power losses are taken into account via a quadratic formulation and a piecewise linear approximation. Computational tests on a small-scale system and on a part of the Milano distribution network are reported.

中文翻译：

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具有布局约束和损耗的城市配电网规划中的最优馈线路由

我们解决了在意大利米兰市以最佳方式重新路由城市配电网络的馈线的问题，这带来了一些特殊性和重大的设计挑战。Milano有两个独立的中压（MV）配电网络，以前由两个不同的公用事业公司运营，它们独立且不协调地成长。这导致系统布局效率低下，冗余并且由于不同的操作过程而难以管理。当前负责整个配电系统的公用事业UNARETI旨在优化整合两个MV配电网络，并转向新的特定布局，从可靠性和灵活性的角度来看，这些布局具有优势。我们提出了一种混合整数编程（MIP）方法，用于设计新的网络配置，以满足规划者要求的所谓两步梯形图布局。该模型考虑了主要的电气约束，例如潮流方程，高压（HV）/ MV变电站变压器的热极限，线路热极限以及每个馈线的最大用户数。通过二次公式和分段线性逼近考虑了有功功率损耗。报告了在小型系统和米兰诺分销网络的一部分上的计算测试。通过二次公式和分段线性逼近考虑了有功功率损耗。报告了在小型系统和米兰诺分销网络的一部分上的计算测试。通过二次公式和分段线性逼近考虑了有功功率损耗。报告了在小型系统和米兰诺分销网络的一部分上的计算测试。