Convex Relaxation of AC Optimal Power Flow with Flexible Transmission Line Impedances

Solution of Optimal Power Flow Problems using Moment Relaxations Augmented with Objective Function Penalization

The optimal power flow (OPF) problem minimizes the operating cost of an electric power system. Applications of convex relaxation techniques to the non-convex OPF problem have been of recent interest, including work using the Lasserre hierarchy of "moment" relaxations to globally solve many OPF problems. By preprocessing the network model to eliminate low-impedance lines, this paper demonstrates the capability of the moment relaxations to globally solve large OPF problems that minimize active power losses for portions of several European power systems. Large problems with more general objective…

Optimal Adaptive Droop Design via a Modified Relaxation of the OPF

The ever increasing penetration of Renewable Energy Resources (RESs) in power distribution networks has brought, among others, the challenge of maintaining the grid voltages within the secure region. Employing droop voltage regulators on the RES inverters is an efficient and low cost solution to reach this objective. However, fixing droop parameters or optimizing them only for overvoltage conditions does not provide the required robustness and optimality under changing operating conditions. In this paper, a convex optimization approach is proposed for reconfiguring PV and QV droop regulators d…

多项式优化中的稀疏凸松弛

Sparse convex relaxations in polynomial optimization

该研究提出单项式模式概念，为多项式优化稀疏方法提供统一视角，整合多类现有松弛方法，推导灵活对偶理论，并通过实验验证了基于模式的稀疏松弛的实际应用优势。

Phase Retrieval Meets Statistical Learning Theory: A Flexible Convex Relaxation

We propose a flexible convex relaxation for the phase retrieval problem that operates in the natural domain of the signal. Therefore, we avoid the prohibitive computational cost associated with "lifting" and semidefinite programming (SDP) in methods such as PhaseLift and compete with recently developed non-convex techniques for phase retrieval. We relax the quadratic equations for phaseless measurements to inequality constraints each of which representing a symmetric "slab". Through a simple convex program, our proposed estimator finds an extreme point of the intersection of these slabs that i…

基于可变阻抗的潮流控制对可再生能源并网的影响

Impacts of Variable-Impedance-Based Power Flow Control on Renewable Energy Integration

本文研究基于可变阻抗FACTS设备的潮流控制对发电成本、碳排放和可再生能源弃电的影响，采用两阶段随机机组组合模型评估，结果表明FACTS安装有效降低三者，且效果受资源位置、高峰需求和发电组合影响。

模块化软超材料中局部变形的阻抗引导可编程传输

Impedance-Guided Programmable Transmission of Localized Deformation in Modular Soft Metamaterials

研究模块化软超材料中局部变形传输问题，提出阻抗引导设计框架，通过建立非线性模型和拓扑优化实现可编程传输，合成模块族，实现多种位移操纵架构及信息处理，为智能材料系统提供见解和途径。