分析应用于微电网中的储能与控制技术

本文主要分析了储能系统对微电网的启动、稳定控制、容量可信度、电能的质量治理等方面的作用,进而提出了微电网中的集中新型储能技术。并且解析了储能系统在微电网应用中的结构和控制策略,同时对微电网的储能与控制技术发展趋势进行预测。     

微电网储能容量优化配置算法仿真

为了确保微电网系统的电能质量和稳定运行,提出基于Benders分解的微电网储能容量优化配置算法。以微电网系统作为研究对象,分析不同储能单元的充放电特性,将储能系统全寿命周期最小成本作为目标函数,组建微电网储能容量优化配置模型。根据模型特点,将模型分解为上下2层子模型,通过Benders分解算法对模型求解,进而获取最优微电网储能容量优化配置方案。经实验测试结果表明,所提算法可以更好完成容量优化配置,经过优化配置后,电网功率波动范围得到了明显降低。     

非线性负载条件下衡量功率畸变率的方法研究

对于含非线性负荷的独立微电网,负荷对系统的冲击导致功率发生严重畸变,如何反映冲击的大小,确定畸变功率是微电网发展中亟待解决的问题。针对含脉冲负载的独立直流微电网,忽略频率畸变的影响,对非正弦条件下的有功功率及其波动量进行推导,并对如何衡量功率波动的大小进行研究。依照相关标准搭建含柴油机-整流器-脉冲负载的微电网实验平台,测得系统运行时三相电压va、vb、vc及三相电流ia、ib、ic的变化曲线,基于AKAGI H的瞬时功率理论在时域中分析其有功功率,并采用Clark变换推导有功功率的功率波动量,定义功率波动率以衡量含脉冲负载独立直流微电网功率波动的大小,为提高电能质量、储能容量的配置提供新思路。     

微电网的建模仿真研究

研究微电网的建模仿真问题,针对微电网中的微电源种类多样且输出特性各异,由传统的简易微电源模型所构成的微电网平台很难对现今微电网的研究进行仿真.针对以上情况,构建了结构、功能完整的风电机组、燃料电池、带有MPPT(最大功率点跟踪)光伏电池以及柴油发电机等微电源模型,及具有调频作用的二次负载模型,仿真验证了所建模型的合理性及有效性.在此基础上,又构建了一个含多种能源负荷的微型电网模型,对负荷突变及严重故障的条件下微电网维持电能质量和快速恢复的能力予以评估,结果表明所构建的微电源模型和微电网模型能较好地仿真实际情况,为微电网的进一步研究提供了良好的仿真平台.     

区块链技术在微电网中的应用初探

由于微电网的交易模式还在探索之中,本文尝试用区块链技术来解决此问题,并对此展开研究。文章首先从特点、分类和基本框架这几个方面来对区块链展开简要的介绍,然后分析了微电网交易的特点,得到了两者都存在去中心化、智能化、安全可靠等共性,这样才有了区块链应用于微电网交易的基础。并在此基础上建立了微电网电能交易的基本框架,能量流方面通过区块链与物联网技术的相互配合来实现,信息流方面引入区块链后,信息流更加智能可靠。然后,对其中的技术实现进行了分析探讨,明确了微电网交易中的记账权,同时又提出了两种激励新能源参与消纳的机制。最后,说明了区块链技术在电能交易上所面对的难题,主要是能量流受到现实的制约和资源问题。     

基于精确分类和最优匹配机制微电网交易决策方法

随着国家对电力市场改革的不断推进和售电市场的优化,微电网将成为未来电能发展和电网运营管理改革的重要载体。为了提升产消者和消费者的订单匹配效率以及经济效益,首先提出了一种基于区块链技术的微电网电能安全交易,利用双链完成交易双方信息的认证,并提出基于Shapley值分配合作博弈的定价策略。其次,对参与微电网交易的消费者进行精确分类,提高订单交易匹配效率。再次,在订单交易阶段提出基于总优先指数的匹配满意度函数,建立满意稳定的微电网交易双边匹配模型。最后,交易双方通过智能合约完成无第三方信任机构的交易结算。算例结果表明,基于区块链技术和最大满意度及稳定性的微电网交易方法可以完成微电网内部的直接交易,保证了微电网交易的稳定性,并提高了参与微电网交易双方的满意度及匹配稳定性。     

基于改进的可拓层次分析法的电能质量综合评估

为了对电能质量进行客观、综合地评估,以电能质量分析与监测系统的数据为研究对象,以可拓学与层次分析法为基础,并就可拓层次分析方法加以改进,提出了一种新的电能质量评估方法,并利用实际数据进行了验算,相关分析结果表明这种方法能够有效地区分电能质量等级,并对电能质量进行定性和定量评估。     

基于BP神经网络和遗传算法的光伏功率预测的研究

随着光伏发电在社会的大规模应用,加之其波动性和间歇性等特点,使得光伏发电功率预测对微电网控制策略研究、电网电能调度和提高电网电能质量显得更加重要;遗传算法(GA)被运用来对建立的BP神经网络模型的初始权值和阈值进行优化,不仅加快了BP神经网络的收敛速度而且提高了BP神经网络的的预测准确度,实验结果显示采用的预测方法获得了较好的预测效果。     

微电网HHT谐波检测与时频分析方法

为解决微电网谐波、突变等复杂非平稳信号的精确检测问题,提出一种基于Hilbert-Huang变换（HHT）的微电网谐波检测与时频分析方法。该方法采用保形分段三次埃尔米特插值法拟合极值点曲线,对谐波信号进行经验模态分解（EMD）,得到有限个固有模态分量（IMF）并进行Hilbert变换,最终计算各个IMF分量的瞬时频率和瞬时幅值,实现微电网谐波等非平稳电能信号的时频特性精确检测。仿真结果表明,该方法能够快速、准确地获取谐波信号频率成分、幅度及电压突变时刻。相对于FFT变换及传统HHT方法具有较高的精度和时域区分特性,可满足微电网谐波微机检测的工程应用需求。     

基于超级电容器与有源电力滤波器组合的电能质量治理装置及其控制研究

为了增加微电网中电能质量治理装置的利用率,利用超级电容储能系统与有源电力滤波器在主电路拓扑上的相似性以及功能上的互补性,提出了一种基于超级电容器与有源电力滤波器组合的电能质量治理装置。文章分析了该组合装置的结构特点和组合原理,提出了组合装置双向DC/DC模块、DC/AC模块的控制策略,给出了组合装置在功率调节和谐波治理两种工作模式下的切换逻辑。仿真结果表明,该组合装置能够根据需要分别表现为功率调节、无功补偿与谐波治理功能,验证了组合装置的合理性和有效性。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

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。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

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.