交流高压真空断路器永磁机构控制器的设计

针对现有的永磁操动机构真空断路器控制电路采用2个直流接触器切换储能电容对分、合闸线圈供电存在控制时间不准确、分散性大、难以与高压综合保护器联动、功耗多、成本高等问题,提出了一种交流高压真空断路器双稳态永磁机构控制器的设计方案,详细介绍了该控制器的硬件电路和软件设计。该控制器具有完整的永磁机构控制单元,可实现合闸、分闸、闭锁以及欠压延时、欠压保护等功能,并为远程通信提供技术基础,在断路器技术参数范围内可保证安全、可靠运行,并可在额定参数范围内进行频繁操作。     

高压断路器操动机构在线监测用角位移传感器

高压断路器操动机构的在线监测是电网发展的一项重要工作,目前监测所用的角位移传感器大多采用单端输出信号方式、输出精确度低且结构复杂、难以满足高压断路器运行工况要求。论文针对目前高压断路器操动机构在线监测存在的不足,在分析高压断路器操动机构角位移监测原理的基础上,研发了一种高压断路器操动机构在线监测的角位移传感器。该传感器主要由永久磁铁、磁敏元件与检测电路板、联轴器及连接轴、信号输出插座等部分组成,可用于在有效调节范围内、规格不同旋转轴的角位移监测;通过联轴器连接被测转轴进行非接触角位移检测,检测磁敏元件与电路安装在螺纹连接的传感器上盖与传感器底座形成的圆柱形密封金属壳体内,检测结果以一对互补的占空比与角位移θ成正比的PWM波形输出,能有效抑制高压断路器运行工况下的强电磁干扰,使监测结果更加准确可靠。     

数字智能控制在机电一体化系统建模技术中的应用

针对机电一体化系统的智能控制升级的要求,在传统操动控制系统的基础之上,以高压断路器操动机构为例,构建了以模糊神经网络PID的算法为核心的电机操动机构控制系统,实现了电机操动机构智能化控制的应用。结果表明：模糊神经网络PID自身具有参数整定和抗干扰的能力,在控制系统仿真实验中,最大速度时的跟踪误差约为0.15 m/s,在智能调控实验中,最大速度时的跟踪误差约为0.23 m/s,证明模糊神经网络PID控制方法具有较好的控制效果和精度,可以运用于电机操动机构的智能化控制。     

高压断路器操动机构的动力学建模与仿真研究

利用UG软件建立了高压断路器弹簧操动机构的三维实体模型,并导入到机械系统动力学仿真分析软件ADAMS中,动态仿真了断路器的运动特性,验证了虚拟样机模型的正确性。着重仿真分析了断路操动机构器的挡板位置、摩擦力、弹簧劲度系数等因素对高压断路器动态性能曲线的影响,为以后高压断路器的优化设计、状态监测及其故障诊断提供了理论依据。     

电力系统高压真空断路器分合闸线圈的烧毁原因及预防策略研究

在对电力系统高压断路器分合闸线圈烧毁的原因进行分析时,可以从投切故障等方面着手。通过研究断路器合闸线圈故障以及操作机构二次回路故障,对分合闸线圈烧毁的问题进行深入分析。本文通过分析影响分合闸线圈烧毁的各种因素,提出了有效维护分合闸线圈烧毁的各项举措。     

基于位移信号的高压断路器机械特性检测系统研究

高压断路器的机械特性为评价其动作性能提供有效的依据,故该文提出了一种利用断路器分合闸过程中动触头的位移信号来检测断路器机械特性的方法。根据断路器动作过程中动作机构的工作原理,该方法选择合适的位移传感器,通过FPGA对位移信号进行采集;然后对采集的存在噪声干扰位移信号进行小波去噪;最后通过辅助触点的状态变化来实现刚分(刚合)时间点的提取并实现断路器分合闸行程和速度的确定。     

基于ARM9/DSP的高压断路器在线监测技术的设计

针对高压断路器在线工作时高电压、大电流而不易使用传感器监测一次线路电流、电压的情况,提供了一种高压真空断路器在线监测方法及一种在线监测装置。首先介绍了该系统的框架结构与功能模块,并详细分析了系统的硬件电路。随后介绍了一种数据处理方法,该方法可实现对高压断路器动触头的行程数据的一系列滤波与修正,同时可计算行程曲线上分合闸换位点,最终得到所需要的关键数据,并将得到的工作状态曲线传至显示终端。     

基于嵌入式技术的断路器分闸速度控制器的设计

为改变断路器的单一分闸特性,基于微处理器设计了断路器分闸速度模糊控制器.研究了配永磁操动机构的断路器系统电气参数与储能电容器电容量的模糊关系,形成了对断路器分闸速度的模糊控制规则,并对控制器的软硬件进行了详细设计.该控制器使用多个储能电容器进行断路器分闸操作,能够实现不同开断条件下的分闸控制.     

10kV高压真空断路器的检查维护方案

10k V高压真空断路器是有效控制电力系统的关键性电器,在运行和操作过程中发现断路器及自带操动机构,小问题不断。本文检修专业出发,介绍10k V高压真空断路器的结构与检查维护方案。     

基于就地数字化的断路器控制系统研究

高压断路器是电力系统的关键开关设备,其运行状态的实时准确掌握是保障其正常发挥功能和较长使用寿命的必要手段。研究了一种基于就地数字化的断路器控制系统,基于多维参量,断路器电气控制回路,断路器控制智能分析模块,通过断路器本体汇控柜里的智能汇控装置采集断路器操作过程的暂态一次电流及恢复电压波形、断路器的操作振动声纹波形以及分合闸线圈的操作电流波形;由就地数字化平台根据断路器操作机构的机械、电气等机理模型对这些波形进行综合识别和关联分析诊断,返回就地智能汇控装置进行断路器状态更新,以便现场人员随时可以在就地掌握断路器当前的状态,并对断路器分合闸控制就行分析,确定断路器状态为正常后可正常进行断路器电气控制的实现。     

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.