计及可再生能源消纳的电热综合能源系统多目标优化模型

可再生能源因其清洁低碳的特点备受能源行业关注。但同时,可再生能源的不确定性也带来了严重的消纳问题。提高电力系统的灵活性去解决可再生能源的消纳问题成为当下研究热点之一。本文突破异质能源间的壁垒,基于电热综合能源系统去探索提高可再生能源的消纳能力。同时,立足于经济性与安全性指标,本文提出了一种多目标优化数学模型,并通过对偶转化和C CG算法对所提模型进行求解。最后,在算例测试中,通过对比电热综合能源系统与电力系统的各种测试指标证明了所提模型的有效性。     

考虑源-荷不确定性的矿山综合能源系统多时间尺度区间优化调度

在高能耗矿山综合能源系统中,为减小乏风、瓦斯、矿井涌水等伴生能源、可再生能源、负荷不确定预测误差对系统的影响,提出考虑源-荷预测不确定性的矿山综合能源系统多时间尺度区间优化调度策略.首先,构建含可再生能源、矿山伴生能源、光热电站的矿山综合能源系统架构;其次,根据电-热响应特性和源-荷不确定性在时间上的差异,建立日前-日内-实时多时间尺度区间优化调度模型.在日前和日内优化阶段,利用区间数描述源-荷不确定性,并通过区间优化方法对伴生能源和可再生能源的实际消纳区间进行优化;日内优化在日前优化的基础上,综合考虑建筑用户热舒适度的模糊性、供热系统的热惯性及热水负荷需求响应调整各设备出力;在实时优化阶段,考虑电负荷需求响应对日内电力设备出力进行修正.最后,通过算例分析验证所提模型和方法的可行性.     

基于主从博弈的综合能源系统优化调度策略

以综合能源系统为研究对象，建立了以综合能源系统运营商为领导者，负荷聚合商为跟随者的主从博弈模型，并使用改进的混沌阿基米德优化算法求解该模型。依据该模型，综合能源系统运营商需根据用户用能情况对系统设备出力进行优化调度并向负荷聚合商制定能源价格，负荷聚合商根据能源价格对用户的用能策略进行调整。仿真实例表明，该主从博弈模型能够有效增强可再生能源发电的消纳能力，可再生能源出力利用率提升了4.45%。     

考虑综合需求响应和电转气的园区综合能源系统优化调度方法

针对园区综合能源系统可再生能源消纳和冷热电负荷波动的问题,引入电转气技术,同时结合可平移电负荷、灵活的热负荷和灵活的冷负荷,建立了考虑综合需求响应和电转气技术的园区综合能源系统优化调度方法,并转变模型构建成为混合整数线性规划模型,通过matlab结合yalmip调用cplex求解器进行求解,快速解决海量数据和约束条件对于求解复杂度的影响。并通过对比算例分析,考虑综合需求响应对于削峰填谷、可再生能源消纳的影响以及园区综合能源系统整体经济性的影响,验证本文所搭建模型的有效性和合理性。     

考虑温度舒适度与碳交易的综合能源系统优化调控

综合能源系统可以实现多能互补、能源梯级利用,但设备间复杂的耦合关系对新能源消纳与源荷波动平抑带来了极大挑战.针对此类问题,本文提出基于舒适度的温差储能与阶梯奖惩碳交易机制的调控模型.首先,在电价需求响应的基础上,构建由舒适度划分的冷热需求响应的温差储能模型.其次,建立以系统运行成本与碳排放量最低为目标的综合调控模型,在...     

计及配电网灵活性的多园区综合能源系统分布式优化调度

多园区综合能源系统与配电网的交互方式决定多能潮流分布和能量传输损耗,进而将直接影响整个系统的优化运行.本文提出了一种计及多园区综合能源系统与配电网之间接入影响的分布式协同优化调度方案.首先,提出一种包含综合能源系统及配电网的双层分布式优化系统架构.然后,以各园区综合能源系统用能成本最低、配电网网损最小为目标,以能源园区接入配电网的位置及配电网网络拓扑为调控手段给出协同优化模型,并通过改进自适应步长交替方向乘子法实现问题分布式求解,实现了系统的整体高效调度,提升了配电网灵活性及园区综合能源系统运行经济性.最后,通过仿真算例验证了本文所提方法的准确性及有效性.     

考虑源荷互动的主动配电网两层优化调度

针对主动配电网中清洁能源消纳率低、负荷侧资源调度不足的问题,提出了一种包含负荷层和主动配网层的两层优化调度模型。负荷层首先根据负荷参与调度的形式不同分类建模,然后通过源荷协调互动调整柔性负荷用电时序及清洁能源的出力;主动配网层则依据分时电价优化系统的综合运行成本,提出禁忌-细胞膜优化算法对模型求解。通过算例对比分析了分层、分类负荷前后三种方案下优化调度的结果,证明了提出的优化调度模型在配网系统经济运行的前提下,可以有效提高清洁能源的消纳率,进一步降低负荷峰谷差,同时验证了算法的有效性。     

基于灰狼算法冷热电联供综合能源优化调度

对于冷、热、电联供综合能源系统优化问题,为了提高可再生能源利用率,故以弃风、弃光量最小和综合能源系统运行经济性为优化目标,建立了含风机、光机、燃气轮机、燃气锅炉等综合能源优化模型.模型的求解使用的改进多目标灰狼算法,得到Pareto解集.针对综合能源系统的约束较多、灰狼算法种群多样性少、容易陷入局部最优等方面,对算法进...     

基于宽度学习预测的可重构多微电网随机优化框架

针对多微电网稳定性差、能量管理复杂等问题，提出一种智能随机优化框架，对可再生能源普及率较高的微电网系统进行优化运行和管理。该模型考虑了电动汽车的高移动充电需求以及可再生能源的随机性。为了减轻车辆对单个微电网的负面影响，采用V2G方案，并与微电网成本函数兼容。作为可再生能源的支持策略，提出一种基于UT框架和宽度学习的深度学习的概率方法，该方法考虑到可再生能源的随机性，将系统运行在安全区域。在此基础上，设计一种基于改进SCE(Shuffled Complex Evolution)的智能优化算法，在全局空间寻找最优解。通过IEEE测试系统检验了该模型的适用性。     

考虑可再生能源成本特征的智能电网优化运行研究

可再生能源(RES)发电的间歇性极易扰乱电网的运行，将可再生能源出力在智能电网运行中充分消纳，对系统运营商来说较为困难，对此，提出一种可将太阳能和风力发电站与电力系统运行有效整合的方法。该方法可用更低的成本和更高供电可靠性来提升电能供应标准。对太阳能电站和风力机组的增量成本特征进行建模，建立计及切负荷量、传输线路的功率损耗、最小母线电压值和最大线路传输功率惩罚项的目标函数，并将其应用于考虑帕累托解的最优潮流计算中。通过IEEE-30节点系统的算例仿真，验证了模型的有效性。     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.     

Editorial: Special issue on recent advances in hybrid control theory and applications

正The demands of a rapidly advancing technology for faster and more accurate controllers have always had a strong influence on the progress of automatic control theory.In recent years control problems have been arising with increasing frequency in widely different areas,which cannot be addressed using conventional control techniques.The principal reason for this is the fact that a highly competitive economy is forcing systems to operate in regimes where     

Information for Authors

正Aim The Journals of Zhejiang University-SCIENCE(A/B/C)areedited by the international board of distinguished Chinese andforeign scientists,and are aimed to present the latest devel-opments and achievements in scientific research in China andoverseas to the world’s scientific circles,especially to stimulateand promote academic exchange between Chinese and for-eign scientists everywhere.     

Enhancing a leaf radiative transfer model to estimate concentrations and in vivo specific absorption coefficients of total carotenoids and chlorophylls a and b from single-needle reflectance and transmittance

The relative concentrations of different pigments within a leaf have significant physiological and spectral consequences. Photosynthesis, light use efficiency, mass and energy exchange, and stress response are dependent on relationships among an ensemble of pigments. This ensemble also determines the visible characteristics of a leaf, which can be measured remotely and used to quantify leaf biochemistry and structure. But current remote sensing approaches are limited in their ability to resolve individual pigments. This paper focuses on the incorporation of three pigments—chlorophyll a, chlorophyll b, and total carotenoids—into the LIBERTY leaf radiative transfer model to better understand relationships between leaf biochemical, biophysical, and spectral properties.Pinus ponderosa and Pinus jeffreyi needles were collected from three sites in the California Sierra Nevada. Hemispheric single-leaf visible reflectance and transmittance and concentrations of chlorophylls a and b and total carotenoids of fresh needles were measured. These data were input to the enhanced LIBERTY model to estimate optical and biochemical properties of pine needles. The enhanced model successfully estimated reflectance (RMSE = 0.0255, BIAS = 0.00477, RMS%E = 16.7%), had variable success estimating transmittance (RMSE = 0.0442, BIAS = 0.0294, RMS%E = 181%), and generated very good estimates of carotenoid concentrations (RMSE = 2.48 µg/cm², BIAS = 0.143 µg/cm², RMS%E = 20.4%), good estimates of chlorophyll a concentrations (RMSE = 10.7 µg/cm², BIAS = − 0.992 µg/cm², RMS%E = 21.1%), and fair estimates of chlorophyll b concentrations (RMSE = 7.49 µg/cm², BIAS = − 2.12 µg/cm², RMS%E = 43.7%). Overall root mean squared errors of reflectance, transmittance, and pigment concentration estimates were lower for the three-pigment model than for the single-pigment model. The algorithm to estimate three in vivo specific absorption coefficients is robust, although estimated values are distorted by inconsistencies in model biophysics. The capacity to invert the model from single-leaf reflectance and transmittance was added to the model so it could be coupled with vegetation canopy models to estimate canopy biochemistry from remotely sensed data.     

Mr. Twinn’s bombes

This article discusses the history and design of the special versions of the bombe key-finding machines used by Britain’s Government Code & Cypher School (GC&CS) during World War II to attack the Enigma traffic of the Abwehr (the German military intelligence service). These special bombes were based on the design of their more numerous counterparts used against the traffic of the German armed services, but differed from them in important ways that highlight the adaptability of the British bombe design, and the power and flexibility of the diagonal board. Also discussed are the changes in the Abwehr indicating system that drove the development of these machines, the ingenious ways in which they were used, and some related developments involving the bombes used by the U.S. Navy’s cryptanalytic unit (OP-20-G).