先进电力电子技术在智能电网中的应用

信息化、数字化、自动化、互动化是智能电网的发展目标,先进电力电子技术是建设智能电网的重要技术手段。从不同角度分析了中国智能电网对先进电力电子技术的需求,展望了中国先进电力电子技术的研究方向和发展预期,介绍了先进电力电子技术的基本内涵及其在智能电网中的应用,着重介绍了灵活交流输电(flexible AC transmission system,FACTS)技术和直流输电(high voltage DC,HVDC)技术在智能电网中的应用,并指出其未来的发展重点。     

19.2 kbps高速数传技术在负荷管理系统中的应用

针对目前南京地区230MHz专网终端数量多、GPRS公网无线信道通信效果差、通信盲区较多的问题,采用最新通信技术,将230MHz负荷管理系统数据通信速率提高到19.2kbps以解决主站站点的容量限制问题,打开系统的发展空间;采用智能路由技术,解决基站覆盖盲区的信号采集问题,并实现路由的自动维护;通过增加终端上线过程以方便调试。实际运行效果表明,以上技术措施较好地解决了目前大型负荷管理系统中存在的由于终端数量过多导致数据巡测时间不够、终端数量发展受限的问题,并有效实现了基站覆盖区域内盲区或盲点终端的可靠通信。     

The future of electronic power processing and conversion

At a workshop held on the Aeolian Islands in Sicily during May 2004 a group of academic and industry engineers from all over the world discussed the medium- and long-term future of power electronics and its applications in specific areas. The following main issues were identified and discussed: The demand is not for power electronic solutions but for system integration of electronic power processing. A more multidisciplinary approach is needed. We will witness a proliferation of energy storage in systems. The technology is in place and the improvement in system performance makes it worth while. A large penetration of power electronics into power systems will happen within the next 25-30 years. The main transmission grid will not be affected. The power electronics development will be in distributed generation and in the loads. The success of the integrated starter/generator (ISG), hybrid, or electric cars depends on political decisions more than on technological advances. However, the success of a recent Japanese hybrid car and the cost of oil could trigger the critical momentum for large-scale use of power electronics in automotive applications. We are moving toward standardized power supply building blocks for computers and other applications. The main push is for lower cost, and production technology becomes the important issue. Demands for improved performance in a diversity of applications will stimulate R&D in power electronics in the future. Intelligent control and energy management will come easily. Thermal and passive component integration is equally important and will require attention.     

Sensing Surrounding 3-D Space for Navigation of the Blind

This article presents a two-dimensional (2-D) vibration array for detecting dynamic changes in three-dimensional (3-D) space during navigation and provides these changes in real time to visually impaired users (in a form of vibration) to develop a 3-D sensing of the space and assist their navigation in their working and living environment. This vibration array is a part of the Tyflos prototype device (consisting of two tiny cameras, a microphone, an ear speaker mounted into a pair of dark glasses and connected into a portable PC) for blind individuals. The overall idea is of detecting changes in a 3-D space is based on fusing range data and image data captured by the cameras and creating the 3-D representation of the surrounding space. This 3-D representation of the space and its changes are mapped onto a 2-D vibration array placed on the chest of the blind user. The degree of vibration offers a sensing of the 3-D space and its changes to the user. It is concluded that the power conception will be associated with the potential of the batteries of the portable computer (notebook). Thus, the visually impaired user has to recharge the batteries after a certain time or carry additional batteries connected to notebook.     

Design and implementation of haptic virtual environments for the training of the visually impaired

This paper presents a haptic virtual reality (VR) tool developed for the training of the visually impaired. The proposed approach focuses on the development of a highly interactive and extensible haptic VR training system (the ENORASI VR training system) that allows visually impaired, to study and interact with various virtual objects in specially designed virtual environments, while allowing designers to produce and customize these configurations. Based on the system prototype and the use of the CyberGrasp haptic device, a number of custom applications have been developed. An efficient collision detection algorithm is also introduced, by extending the proximity query package (PQP) algorithm to handle five points of contact (a case studied with the use of CyberGrasp). Two test categories were identified and corresponding tests were developed for each category. The training scenarios include: object recognition and manipulation and cane simulation, used for performing realistic navigation tasks. Twenty-six blind persons conducted the tests and the evaluation results have shown the degree of acceptance of the technology and the feasibility of the proposed approach.     

Silicon photonics

The silicon chip has been the mainstay of the electronics industry for the last 40 years and has revolutionized the way the world operates. Today, a silicon chip the size of a fingernail contains nearly 1 billion transistors and has the computing power that only a decade ago would take up an entire room of servers. As the relentless pursuit of Moore's law continues, and Internet-based communication continues to grow, the bandwidth demands needed to feed these devices will continue to increase and push the limits of copper-based signaling technologies. These signaling limitations will necessitate optical-based solutions. However, any optical solution must be based on low-cost technologies if it is to be applied to the mass market. Silicon photonics, mainly based on SOI technology, has recently attracted a great deal of attention. Recent advances and breakthroughs in silicon photonic device performance have shown that silicon can be considered a material onto which one can build optical devices. While significant efforts are needed to improve device performance and commercialize these technologies, progress is moving at a rapid rate. More research in the area of integration, both photonic and electronic, is needed. The future is looking bright. Silicon photonics could provide low-cost opto-electronic solutions for applications ranging from telecommunications down to chip-to-chip interconnects, as well as emerging areas such as optical sensing technology and biomedical applications. The ability to utilize existing CMOS infrastructure and manufacture these silicon photonic devices in the same facilities that today produce electronics could enable low-cost optical devices, and in the future, revolutionize optical communications.     

浅议逆变器系统中的电气子回路

电力电子装置内部子回路间的关系常常会给研发或维修工作带来麻烦。本文以PWM电压型逆变器为例介绍了几种电力电子中的隔离电路,归纳了独立子回路之间的隔离方式;分析了造成故障的原因并提出了解决办法,可为电力电子装置的研发和维修工作提供参考。     

Gait analysis of people walking on tactile ground surface indicators.

Tactile ground surface indicators installed on sidewalks help visually impaired people walk safely. The visually impaired distinguish the indicators by stepping into its convexities and following them. However, these indicators sometimes cause the nonvisually impaired to stumble. This study examines the effects of these indicators by comparing the kinematic and kinetic variables of walking on paths with and without indicators. The results suggest that walking on the indicators causes extra movements of the lower extremities such as increased minimum toe heights during the midswing phase, increased peak hip flex moments, and increased peak hip heights. This study also suggests that a functional leg length discrepancy while walking on the indicators is one of the reasons for the extra movements of the lower extremities. Therefore, we designed a new recessed tactile surface to offset the differences of surface depth while walking on the path containing indicators, and found that the newly designed recessed tactile surface was effective in reducing the extra movements while walking on the path in which indicators were installed. These indicators may help both the visually impaired and elderly people with normal vision to walk safely.     

Walking navigation system for the visually impaired using a guide stick

We have proposed an online navigation system for the visually impaired. In our previous system, we used a pedometer and a terrestrial magnetic sensor. This system has the problems of cumulative errors in the measurement of walking distance and errors in the detection of walking direction due to the lean of the terrestrial magnetic sensor. In this paper, we develop another navigation system that uses a guide stick to which is attached a small wheel at the end of the stick instead of a pedometer and a device for keeping the terrestrial magnetic sensor horizontal in order to improve the problems of the previous system. Thus, we can obtain a more exact walking locus. To navigate the visually impaired, we propose a method using auditory signals consisting of voice sound and buzzer. Further, we attach an answering machine to the guide stick to provide the required information whenever requested. To evaluate the navigation system, we conduct walking experiments using blindfolded and visually impaired individuals. It is seen that this system can guide them to a destination at a distance of about 620 m and is useful as a navigation system for the visually impaired. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 119(3): 69–80, 1997     

Power converters and amplifiers (review of "RF Power Amplifiers" by Kazimierczuk, M.K.; 2008) [Book news]

This is a comprehensive textbook covering the fundamentals of RF power amplifiers and their range of applications in radio and TV broadcasting, wireless communications, and radars. It presents accessible coverage of the complex principles of operation of RF power amplifiers and radio power systems. It introduces the fundamental design techniques and procedures for practitioners for RF power amplifiers. All the chapters contain examples and design procedures throughout, with review questions, problems, and references at the end of each chapter. A solutions manual is available for instructors. This textbook is helpful for students as well as for practicing engineers working with RF power amplifiers in such application areas as computers, telecommunications, industrial electronic systems, automotive electronics, radars, medical equipment, and aerospace power technology.     

Power Conversion System Strategies for Fuel Cell Vehicles

PowerConversionSystemStrategiesforFuelCellVehiclesKaushikRajashekara(FellowIEEE;DelphiCorporation,MailCodeERC12 D35,P.O.Box9005,Kokomo,IN46904 9005,USA)Abstract:Powerelectronicsisanenablingtechnologyforthedevelopmentofenvironmentalfriendlyfuelcellvehicles…     

Smart electrical energy networks [review of Power Electronics in Smart Electrical Energy Networks (Strzelecki, R. and Benysek, G.; 2008)] [Book News]

The major aim of this book, a monograph written by an international team of authors, is to present the features, solutions, and applications of the power electronics arrangements likely to be useful in smart electrical energy networks. The book is organized into 12 chapters and includes the following topics: principles of electrical power control; an overview of power electronics converters and controls; quality problems in smart networks; high frequency AC power distribution platforms; integration of distributed generation with electrical power systems; active power quality controllers; and grid integration of wind energy systems, among other topics. The book includes numerous practical examples and very good illustrations that highlight the discussed topics. Each chapter begins with an introduction and is supplemented with a summary and list of references at the end. The book can be used a s a reference for advanced senior-level courses.     

仿生学在电力电子系统设计中的应用

基于生物可靠性机理,系统地探讨了高可靠性电力电子系统的设计理论和方法,包括自律分散控制、冗余设计、自复制和自修复、智能化设计、自适应控制及自组织控制。利用这些仿生设计理论和方法,可提高电力电于系统的可靠性。提出了自律单元和自律分散电力电子系统等重要概念, 并指出:自律单元应具有自律可控性和自律协调性,自律分散的电力电子控制系统基于自律单元;自律分散控制系统代表了以后高可靠复杂功率变换器系统的一种极具前景的发展方向。最后,基于生物系统的自律分散控制思想,设计了一种新颖的单相逆变器。应用实例表明,仿生学在电力电子技术中,尤其在高可靠性电力电于系统设计中,有着广阔的应用前景。     

基于盲恢复的POCS图像超分辨率重建

在传统凸集投影(POCS)算法基础上,考虑到算法对于初始图像的依赖性,尝试通过引入近似点扩散函数检测(APEX)盲解卷积技术,对POCS算法的初始参考图像进行盲恢复,然后再进行超分辨率图像重建。仿真实验证明,APEX盲恢复后的初始图像,相比原初始图像,更加接近真实图像。重建后,直观上图像的清晰度有了一定程度的提高,由于更好地抑制了噪声,表现在PSNR有了一定的提升;另外,由于APEX的引入,改进算法在一定程度上降低了原算法对初值的依赖程度,增强了POCS算法的鲁棒性。     

磁耦合谐振式无线电能传输技术研究动态与应用展望

近年来,无线电能传输技术由于其独特的自身优势而受到了越来越多的关注。文中重点分析了磁耦合谐振式无线电能传输技术的发展动态与应用现状,介绍了磁耦合谐振式无线电能传输技术发展现状以及尚待解决的问题。详细阐述了无线电能传输技术的机理模型、关键技术、电磁环境、技术标准及相关应用中的瓶颈问题等。最后,在深入探讨当前研究热点的基础上,对该技术的发展动态进行了总结与展望。     

The Smart way to get DMFC products into the market

While many companies worldwide are developing direct methanol fuel cells for use in portable electronics, SFC Smart Fuel Cell AG in Germany has grabbed a leading position with its innovative DMFC technology, and is already rolling out commercial products that are being integrated into mobile power solutions. The company has also established an international distribution infrastructure for its methanol fuel cartridges, and is ready to take on the world’s electronics giants in getting its products into a power-hungry marketplace.     

电力电子前沿技术与应用专辑主编评述

随着宽禁带半导体器件和无线电能传输等新技术的快速发展,以及基于电力电子技术的新型设备在电力系统中的大规模应用,电力电子技术作为高效电能转换和传输的关键支撑技术,得到国内外研究人员广泛关注,近年来涌现了众多前沿热点技术与新型应用。比如变流器的拓扑设计、老化监测与稳定性控制等等。基于电力电子众多前沿技术与应用的最新研究进展,《电源学报》特别邀请中国电源学会青年工作委员会推出“电力电子前沿技术与应用”专辑,以期推进电力电子前沿技术与应用难点和热点问题的探讨。     

柔性电气开关技术及其应用

柔性电气开关技术是将高频电力电子开关应用于电磁开关,以屏蔽方式实现两种技术理想化互补。由此研发的柔性电力电子控制与保护开关组件,以高频电力电子技术高性价比地处理低频低压电磁开关的动态缺陷问题。电路分析与实验验证表明此技术可行。     

Charge ahead [ultracapacitor technology and applications]

Ultracapacitors, also known as electrochemical double-layer capacitors (EDLCs) or supercapacitors have been around for decades and first appeared as low-power, low-energy, long-life backup devices, but until recently had few other applications. This article outlines the technology behind ultracapacitors and presents a variety of current applications, including backup power supplies, power boosters in portable electronics, and automobile electronics. Also briefly discussed are cost issues and possible future developments.     

电力电子技术在风力发电中的应用

随着经济的快速增长和社会的全面进步,我国的能源供应和环境污染问题越来越突出。开发和利用可再生能源的需求更加迫切。风能作为可再生能源中最重要的组成部分和唯一经济的发电方式,由于其清洁无污染、施工周期短、投资灵活、占地少,具有良好的社会效应和经济效益,已受到世界各国政府的高度重视。随着现代电力电子技术以及变频调速技术的迅速发展,其在风力发电中的应用也更为广泛。重点介绍了电力电子技术在风力发电中的主要应用,包括风力发电系统的分类;双馈风力发电双向变频器的优缺点;风力发电的输送方式等。最后对风力发电的前景进行了展望。