多区域电力系统协调调峰及峰谷互济运行方式分析

利用不同区域负荷和可再生能源发电出力的时空互补特性,研究实现跨区域协调调峰的方法,可为能源互联网的电网规划、运行方式设计提供重要决策支撑。从多区域的源荷特性分析出发,基于调峰评价指标体系分别进行了多区域调峰的确定性分析和不确定性风险评估,给出了典型峰谷互济运行方案,并从技术、经济两个方面分析了不同方案下的跨区联网调峰经济效益,得出了一种多区域联网的协调调峰的典型运行方式及经济性评估结果。     

面向新型城镇化的未来配电网形态研究

根据新型城镇化的内在要求,同时考虑到微电网、多能互补、需求侧资源的引入,未来配电网将全面呈现出新的格局和形态特征。从网架结构、自愈控制、能量调度、市场交易4个方面对传统配电网形态进行了总结,并在此基础上对未来配电网形态进行了展望,并提出了配电网各阶段的发展目标和相关建设指标的构想。     

Finite-time H∞ control of uncertain networked control systems with randomly varying communication delays

This paper is concerned with the problem of finite-time $H_{\mathrm{\infty }}$ stability analysis of uncertain discrete-time Networked Control Systems (NCSs) with varying communication delays in a random fashion. Both measurement and actuation delays are modeled by two independent Bernoulli distributed white sequences. A dynamic output feedback controller is designed to realize finite time control for this class of NCSs with prescribed $H_{\mathrm{\infty }}$ performance level. An iterative algorithm is developed to compute the controller's parameters by means of the Cone Complementarity Linearization Method (CCLM). The validity and feasibility of the proposed stability criterion are confirmed via numerical simulation examples.     

基于梯度双面互补特性的级联快速目标检测

针对目标检测中精度和速度难以兼顾的问题,借助视觉注意理论中的目标感知与识别机制,分析目标描述中梯度幅值与梯度方向信息之间具有的互补性,提出了基于两层级联梯度特征的快速目标检测模型,可有效描述类无关和类相关检测器.一方面,采用梯度幅值特征,从滑动窗口采样中获得候选目标提议,大幅降低了验证窗口的数量,确保检测速度,另一方面,利用级联方式学习训练多个子检测器,可更好实现不同尺度变化下的目标检测精度.PASCAL数据集上的实验结果,解释了级联梯度特征对目标结构描述的有效性,表明了该文方法在与现有先进方法的检测精度相当的前提下,可极大提升检测速度.     

Linear Complementarity Framework for 3D Steady-State Rolling Contact Problems Including Creepages with Isotropic and Anisotropic Friction for Circular Hertzian Contact

In this article, the problem of 3D steady-state rolling contacts with dry friction for circular Hertzian contacts is formulated mathematically as a linear complementarity problem (LCP). The complementarity variables are the traction and the relative slip of contact regions, in which a polyhedral friction law is employed. The present work uses the general expressions describing the surface deformations due to uniform traction over a rectangular area on an elastic half-space to derive the influence coefficient matrix for rolling contact problems. Three possible creepage types—that is, longitudinal, lateral, and spin creepage—are considered in this work. Firstly, the numerical results are verified against the existing numerical solutions and good agreement has been found. Secondly, the anisotropic friction is studied by the verified approach. Some numerical examples are provided to illustrate the current LCP method for both isotropic and anisotropic friction in which the combined effects of the three kinds of creepage on the traction distribution are shown.     

A Complementarity Problem–Based Solution Procedure for 2D Steady-State Rolling Contacts with Dry Friction

The problem of steady-state rolling contact between two cylinders with dry friction was formulated into standard linear complementarity problems (LCPs) using the explicit physical definition. For normal contacts, the complementarity variables are the normal pressure and the gap. For the tangential contact, the traction distribution and relative slip are the variables obtained by solving the LCP. The frictional behavior is assumed to be governed by the Coulomb friction law, and LCP formulations of both similar elastic (Carter problem) and dissimilar elastic rolling contacts are presented in this work. Good agreement was found between the current LCP approach and publicly available software for both the rolling contact of similar elastic and dissimilar elastic cylinders. Moreover, the surface roughness was taken into account in this article by the verified approach. The results show the initial slope of the traction-relative creepage curve decreases as the surface roughness increases.     

Formulation and comparison of algorithms for frictional contact problems

This paper presents two algorithms for solving the discrete, quasi-static, small-displacement, linear elastic, contact problem with Coulomb friction. The algorithms are adoptions of a Newton method for solving B-differentiable equations and an interior point method for solving smooth, constrained equations. For the application of the former method, the contact problem is formulated as a system of B-differentiable equations involving the projection operator onto sets with simple structure; for the application of the latter method, the contact problem is formulated as a system of smooth equations involving complementarity conditions and with the non-negativity of variables treated as constraints. The two algorithms are numerically tested for two-dimensional problems containing up to 100 contact nodes and up to 100 time increments. Results show that at the present stage of development, the Newton method is superior both in robustness and speed. Additional comparison is made with a commercial finite element code. © 1998 John Wiley & Sons, Ltd.     

Modeling and analysis of strategic forward contracting in transmission constrained power markets

Taking the effects of transmission network into account, strategic forward contracting induced by the interaction of generation firms’ strategies in the spot and forward markets is investigated. A two-stage game model is proposed to describe generation firms’ strategic forward contracting and spot market competition. In the spot market, generation firms behave strategically by submitting bids at their nodes in a form of linear supply function (LSF) and there are arbitrageurs who buy and resell power at different nodes where price differences exceed the costs of transmission. The owner of the grid is assumed to ration limited transmission line capacity to maximize the value of the transmission services in the spot market. The Cournot-type competition is assumed for the strategic forward contract market. This two-stage model is formulated as an equilibrium problem with equilibrium constraints (EPEC); in which each firm's optimization problem in the forward market is a mathematical program with equilibrium constraints (MPEC) and parameter-dependent spot market equilibrium as the inner problem. A nonlinear complementarity method is employed to solve this EPEC model.     

Dynamical approach to complementarity of interferometers

The complementarity for wave-like and particle-like properties of a quantum mechanical particle in the Mach–Zehnder interferometer is investigated by means of the dynamical approach. Measurement devices are placed on the paths of the interferometer to obtain the information of a propagating particle. The which-path information of the particle and the fringe visibility of the interferometer are derived by considering the dynamics of the particle and devices. When each device consists of a single qubit, the maximum amount of the which-path information is obtained and the complementary relation is examined.     

Complementarity of circular economy practices: an empirical analysis of Chinese manufacturers

In recent years, circular economy (CE) is receiving increasing attention worldwide and is intended to integrate economic activity and environmental wellbeing in a sustainable way. The CE mainly focuses on both the front (eco-design, ECO) and back ends (reverse activities, RA) of operations and production at the firm level. However, what is missing in the literature are the synergistic effects between the two practices on corporate social responsibility (CSR) performance. Drawing on systems theory, this paper used panel data of Chinese manufacturing firms over the period from 2013 to 2015 that was collected from Chinese Research Data Services Platform (CNRDS) and Rankins CSR Ratings (RKS) databases and performed a series of regression tests to see whether complementarity exists between them and their effects on CSR performance. The results show significant complementarity between ECO and RA in improving CSR performance. Furthermore, building on systems theory, three kinds of enablers are identified as essential for promoting the interaction of subsystems and the complementarity of ECO and RA, including CSR vision as an internal enabler within the system, an environmental management system as a system regulation, and supply chain cooperation as an external enabler from the environment.