The global progress toward one standard, one product, one mark for explosion-protected apparatus-the IECEx scheme

This paper is an update to the 1999 IEEE Petroleum and Chemical Industry Committee paper titled "The Impact of the IECEx Scheme on the Global Availability of Explosion-Protected Apparatus" and further addresses the advantages and possible concerns regarding the IECEx Scheme from the perspective of six international hazardous locations (HazLoc) testing and certification organizations from Brazil, Canada, France, Germany, Ukraine, and the US.     

德国R.STAHL公司防爆电器产品选介

新型钢板式防爆照明灯具 R. STAHL公司生产的危险场所用6014系列薄钢板照明灯具系统已通过检验,目前又有了新式设计 ,新型灯具为用户提供了更大的方便. 外壳前面为平面玻璃, 外形平滑无锐边. 中央锁和自动电源装置分开,开盖非常方便. 玻璃罩和反射器铰接在一起,很容易接近内部元件, 所以接线方便.     

A novel scheme for global scattering center modeling of radar targets

A novel scheme for extracting the global scattering center model of radar targets is proposed in this paper. The 2D/3D scattering center models can be reconstructed based on the wideband measurements at different viewing angles. The sphere spreading of the 1D scattering center projections is exploited. The 1D-2D/3D scatterer map (OTSM) is designed to manifest the high dimensional scattering characteristic of radar targets. The Hough transform and the least squares method are used to extract the stable scattering centers and their scattering coefficients. This modeling method does not need a high density of the spatial grid, which greatly cuts down the necessary original data. The model built in this way describes the stable point scattering mechanisms in a large spatial extent and can be extrapolated to other frequencies in the optical region. Examples verify the validity of both the model and the method. __________ Translated from Chinese Journal of Radio Science, 2007, 22(3): 436–441 [译自: 电波科学学报]     

A global dynamic error driven control scheme for static VAR compensators

The paper presents a novel static VAR compensator SVC control scheme. The new SVC control strategy is validated on a single machine infinite bus power system with a dynamic nonlinear load.     

Technologies for the future global electrical power market—impact of deregulated markets

The increasing competitive forces of the past 20 years have induced production of power generation equipment with vastly improved efficiency and reliability, and much lower emissions. That technology growth will continue, which will assist in meeting the needs of Asia's booming power markets with minimal environmental damage.     

A generalized global adaptive tracking control scheme for robot manipulators with bounded inputs

In this work, a generalized adaptive scheme for the global motion control of robot manipulators with constrained inputs is proposed. It gives rise to various families of bounded adaptive controllers defined through a general class of saturation functions. Compared with adaptive tracking control algorithms previously developed in a bounded input context, the proposed adaptive approach guarantees the motion control objective for any initial condition, avoiding discontinuities throughout the scheme, preventing the inputs to reach their natural saturation bounds, and permitting innovation on the saturating structure through its generalized form, giving a wide range of possibilities for performance improvement. Experimental results corroborate the efficiency of the proposed scheme. Copyright © 2014 John Wiley & Sons, Ltd.     

The neighbourhood school in the global village

Access to the Internet is transforming classrooms in many ways. Students from anywhere can directly access people and information resources from anywhere else. Innovative educational materials can quickly become available throughout the world, not just throughout a school. Students can find up-to-date information and personal mentors without leaving their desks. Teachers can develop and participate in professional peer groups nationally, even internationally. We are exploring a local neighborhood view of educational networks. We describe three facets of this endeavor. First, we directly and pervasively involve community groups, for example, public school teachers and senior citizens, in defining and developing technology to address their needs and to facilitate their goals, Second, we seek to leverage and develop neighborhood resources by facilitating collaboration throughout the community via computer mediated communication (email, chat, shared whiteboards and notebooks, video conferencing). Third, we view the entire community as the learning community, and view local schools as a forever-unfinished community project (D. Schuler, 1996). Our project leverages the networking infrastructure of the Blacksburg Electronic Village (BEV), an advanced community network located in Blacksburg, VA, a college town of about 36000 in rural Appalachia (USA)     

The global state of carbon

The world's newest energy industry, carbon capture and storage (CCS) from coal and gasfired power stations, is on the cusp of extreme growth. Or is it? Some would argue that, when the true costs and technological challenges become apparent, CCS may well fade quickly from sight. But who's right?     

中心城区光纤入户方案探讨

论证了中心城区建设智能配电网的可行性,并以中心城区用户侧通信光纤入户实施方案为切入点,提出了光纤到楼和光纤到户的组网接入方案,并进一步结合中心城区的特点,给出了典型供电区中商贸区、住宅区以及工业区的光纤入户建设改造方案。     

保护方式方案设计的有效性

0前言 2002年1月7日,110kV静德变腈纶3991线过流II段动作,出线断路器跳闸、该线路与静德变镇临3992线均为金甬腈纶公司35kV总降站专线.腈纶总降站主运行方式为2条进线(腈纶3991,镇临3992)带2台主变,主变高低压侧均分列运行.     

The impact of the MIT-BIH Arrhythmia Database

The MIT-BIH Arrhythmia Database was the first generally available set of standard test material for evaluation of arrhythmia detectors, and it has been used for that purpose as well as for basic research into cardiac dynamics at about 500 sites worldwide since 1980. It has lived a far longer life than any of its creators ever expected. Together with the American Heart Association Database, it played an interesting role in stimulating manufacturers of arrhythmia analyzers to compete on the basis of objectively measurable performance, and much of the current appreciation of the value of common databases, both for basic research and for medical device development and evaluation, can be attributed to this experience. In this article, we briefly review the history of the database, describe its contents, discuss what we have learned about database design and construction, and take a look at some of the later projects that have been stimulated by both the successes and the limitations of the MIT-BIH Arrhythmia Database     

配电网络数据库的设计方案

分析研究了基于无线通信系统构建的配电网络数据库。数据库的设计成功与否对于整个系统的运行效率和功能实现起着举足轻重的作用。针对无线网络的特性 ,以及配电自动化系统数据的规划管理问题 ,提出了将数据进行分层分类的管理方法 ,同时结合具体工程的需求 ,进行详细阐述。本方法对于同类工程数据库的设计 ,具有一定的指导意义     

The function and composition of the global industrial grounding system

This paper describes the basic functions of, and the parts that make up, the global grounding system. It discusses the destructive effects on equipment and the danger to human life presented by the existence of high-frequency lightning-surge currents in the earth or ground. Emphasis is on the important role of the global grounding system in minimizing the attendant hazardous voltage gradients that occur in the ground surface. The effect of 60-Hz-frequency ground-fault current in seeking a path in closest proximity to the outgoing power conductors within its ground-fault island is asserted. The operation of wye-delta-wye transformers to interconnect a resistance-grounded industrial system to a solidly grounded high-voltage utility system is explained without the customary utilization of symmetrical components.     

数字化变电站光缆编码方案研究

目前数字化变电站的建设已由理论研究走向工程实践阶段,大量光缆、网络介质的使用代替了常规控制电缆,结合数字化变电站的建设提出了一种便于设计、施工、运行维护的光缆、网络介质编码方案。     

The impact of vehicle-to-grid on the distribution grid

Plug-in hybrid electric vehicles (PHEVs) can be connected to the power grid. The power flow of this connection can be bidirectional, so vehicles can charge and discharge. This vehicle-to-grid option can aid to improve grid efficiency and reliability. A simulation covering an entire day is essential to obtain an accurate assessment of the impact of PHEVs. It is important to know when, statistically, vehicles are available for charging or discharging. In this work is shown that uncoordinated charging of PHEVs in distribution grid can lead to local grid problems. Therefore, coordinated charging and discharging is investigated and a voltage constraint is implemented. These vehicles can support the grid in terms of voltage control and congestion management. In that way, the distribution grid can handle more PHEVs without reinforcements. Distributed generation units are more common nowadays in the distribution grid with some of these generation units based on intermittent renewable resources. This paper shows that there could be a good combination with PHEVs as they can provide storage to take care of the excess of produced energy and use it for driving or release it into the grid at a later time. In that way, consumption and generation are more efficiently matched.     

智能阶段式电流保护方案设计

在中、低压配电网络中,传统三段式电流保护系统的效果直接受电网接线及电力系统运行方式影响,往往难同时满足灵敏度和保护范围的要求。本文提出了实现阶段式电流保护智能化的设计方案。     

电力线载波通信方案设计

低压电力线载波通信既有明显的优势，又存在着强的噪声干扰，导致高的误码率，制约着它的推广应用。本文从有效提高通信成功率出发，提出了过零点通信、静态软件中继技术、通信时段选择等概念，并给出了三级系统的设计方案，可较大幅度地提高系统的性价比。文中还给出了测试数据。实践结果表明，上述措施是有效的。