Towards variance-matrix characterization of complementarity relations in a continuous variable system

We discuss complementarity relations in a bipartite continuous variable system. Building up from the work done on discrete d-dimensional systems, we prove that for symmetric two-mode states, quantum complementarity relations can be put in a simple relation with the elements of the variance matrix. When this condition is not satisfied, such a connection becomes non-trivial. Our investigation is the first step towards an operative characterization of the complementarity in a scenario that has not been investigated so far.     

基于峰谷分时电价的某工业园区多能互补系统多情景运营优化模型

为了提升用户负荷需求与清洁能源供应匹配度,需采取需求响应措施,改变用户用电习惯以配合清洁能源发电。基于此,先构建了综合考虑机组出力和用户负荷转移意愿的需求响应价格驱动模型,制定了某工业园区峰谷分时电价;其次,以峰谷差、清洁能源消纳量和工业园区售电商收益为多目标函数,设计了多情景优化模型;最后,利用GAMS软件进行算例分析。结果表明,工业园区多能互补系统在促进清洁能源消纳等方面具有一定的积极作用,但若要进一步提升清洁能源利用量,实施园区峰谷分时电价尤为必要,分时电价的实施促使清洁能源消纳量至少增加了116.47MW,进一步验证了所提模型的有效性和可行性,为工业园区多能互补系统中提升清洁能源利用率提供了重要参考。     

基于典型场景集的智能园区多能源微网多目标配置优化研究

构建面向智能园区的多能源微网是实现不同类型物理能源系统耦合,提高可再生能源终端能源消费占比的重要途经。通过制定恰当的多能源微网规划,对于保证多能源微网项目投资收益以及推动多能源微网有序发展具有重要意义。鉴于此,该文以园区级多能源微网为研究对象,在利用隐马尔可夫构建典型场景集以压缩系统历史数据的基础上,构建多能源微网配置多目标优化模型架构,并利用某园区实际负荷数据和分布情况,对比分析不同情景下2种不同配置方案的结果和优劣势,定量阐述了多能源微网在降低系统排放强度和系统投资成本方面的优势。     

Determination of Maximum Loadability by a Mixed Complementarity Formulation of the Adjusted Power Flow Problem

The ever-increasing demand for power leads to increased loading on the power system. It is necessary to determine the maximum loadability of power systems so that a sufficient margin can be maintained. Maximum loadability can be determined by solving the power flow equations successively while increasing the loading gradually; conventionally, the unadjusted power flow problem is solved. This also helps in determining the voltage profile with respect to loading. However, determination of loadability margin by the solution of adjusted power flow problem is challenging in the presence of certain limits such as the limits of tap-changing and phase-shifting transformers, and the operating limits of Flexible AC Transmission Systems (FACTS) controllers. In the course of determination of maximum loading, it is likely that these limits are encountered. A novel method for systematic handling of these limits is presented in this paper. A Mixed Complementarity Problem formulation is proposed for inclusion of the limits of tap-changing and phase-shifting transformers, and FACTS controllers. The proposed method is tested on the IEEE 300 bus system and the WSCC 9 bus system in the presence of FACTS controllers.     

基于主从博弈理论的能源互联配电网多能互补协调故障恢复方法

针对能源互联配电网故障恢复的问题,采用主从博弈理论进行建模,所建立的能源互联配电网故障恢复模型计及了多个能源子网之间的多能互补协调。以发生故障后电能子网开关状态为主体博弈者的策略,以能源互联配电网故障恢复后系统的失电负荷量最小为主体博弈者的支付;以包括电能子网、热能子网、气能子网以及交通子网在内的各能源子网优化运行计划调整为从体博弈者的策略,以系统在故障期间综合运行成本最小为从体博弈者的支付,并计及各能源子网运行的必要约束。主体博弈者在提供故障发生后开关状态的同时从体博弈者对能源互联配电网的优化运行计划进行调整。仿真算例表明,能源互联配电网相比于传统配电网,系统在故障恢复之后的运行经济性以及可靠性均更高。     

基于泛在电力物联网的多能互补综合能源服务平台建设及应用

针对江苏省无锡市红豆工业园能源利用效率低与管理模式粗放的问题,国网江苏省电力有限公司无锡供电分公司通过拓展综合能源服务市场,从构建园区泛在电力物联网、实现园区多能互补与管理一体化、建立园区市场化交易机制3个方面,在工业园搭建了基于泛在电力物联网的多能互补综合能源服务平台,实现了区域能源科学调度和协同运行,提升了客户能源管理的精细化水平,降低了企业用能成本。     

多能源网络的广义电路分析理论——（一）支路模型

多种能源形式的互补与耦合为多能源系统集成带来巨大价值,但不同能源形式遵循不同的物理规律和数学表征形式,为综合分析与协同优化带来了挑战。文中基于拉普拉斯变换这一分析系统动态过程的有力工具,提出了多能源网络的广义电路分析理论。首先,建立了多能源网络支路层能量流的统一数学方程,提出了以拉普拉斯变换为基础的广义电路建模方法,将多能源网络在时域的复杂传输特性转换为拉普拉斯域简单的代数问题,提出了各能源系统能量流的分布参数电路模型,进一步提出了以"支路"为整体单位的支路层能量流集中参数传输模型。文中提出的多能源网络广义电路支路模型能够科学地分析支路层能量流的稳态与动态特性,揭示多能源网络能量流的共性,为多能源系统全网络分析奠定基础。     

A quadratic complementarity problem related to the optimal design of a pipeline freely resting on a rough sea bottom

A submarine pipeline resting on a rigid, frictionless seabed assumes an equilibrium configuration which can be determined by solving a unilateral contact problem, i.e. a quadratic program or a variational inequality.When the sea bed is irregular, its profile along the sealine can be modified, in present offshore technology, by means of costly trench excavations or artificial supports, in order to avoid excessive bending moments in the pipe. Thus, the problem arises of determining the minimum cost of the profile changes provided that a specified curvature is nowhere exceeded.This optimal design problem is solved by assuming a quadratic cost function and reducing it to a sequence of convex quadratic programming problems leading to the optimal design situation. Upper and lower bounds on the absolute minimum cost and optimality conditions are established. A suitable algorithm for solving the problem in a finite number of steps is developed. Its generalization to allow for ‘fixed charges’ due to the equipment mobilization cost is presented. Two numerical examples illustrate the optimum (minimum cost) proposed design method.     

Indirect identification of yield limits by mathematical programming

An elastic-perfectly plastic discretized structure subjected to given proportional loads, undergoes displacements, some of which are measured; on the basis of these experimental data assumed as exact (unaffected by measurement errors) the yield limits are sought, whereas the elastic and geometric properties are known. This special problem of identification (or inverse problem in structural elasto-plasticity), under suitable hypotheses of piecewise linear yield surfaces and no local unstressing under increasing loads is shown to be amenable to the minimization of a convex quadratic function under linear and (nonconvex) complementarity constraints. Various alternative solution procedures are proposed. Among these the most promising method from the computational standpoint, consists of two phases: (1) minimizing, under linear constraints only, a nonconvex quadratic function of the plastic strains and of the parameters to identify (thus enforcing by penalization the fulfilment of complementarity); (II) checking the optimality of the solution (and moving from a possible local minimum to the global one) by a procedure based on recent results from quadratic complementarity theory.The mathematical programming method developed for the indirect identification of yield limits is tested by means of examples with encouraging results.     

Berlin and Warsaw: in search of a new role in the European urban system

After 1989, the cities of Central and Eastern Europe were engaged in an inter-urban competition, a process characteristic of the urban scene since the beginning of European integration. Being a topic of great interest to researchers, a large body of literature has accumulated on the observed role of capital cities in the region as well as on their potential role in the future. Several researchers have focused on the position as well as the interdependence of Berlin and Warsaw—two urban nodes in what is hypothesized as a future West–East development trajectory (see Domański, 1999). The present paper deals with the emergence and development of metropolitan functions in these two cities. It is based on a comparative research project, which involved a series of structured, in-depth interviews with planners and policy-makers in Germany and Poland conducted by the author during the period 2001–2003. The paper discusses the development factors and their contributions to the metropolitan potential of Berlin and Warsaw. The identification of these factors is a starting point for determining the future position and rank of these two capital cities in the European urban system. The analysis is complemented by a comparison of trends in the employment structure of Berlin and Warsaw during the period 1994–2002. The results allow the author to evaluate some hypotheses posed in strategic planning documents concerning Berlin and Warsaw.