变压器消防水喷雾系统设计体会

火力发电厂中大量使用油浸变压器,而变压器的安全问题直接影响到火电厂的正常运行。因此对于油浸变压器必须进行准确、合适的消防设计。     

认清形势，在产业结构调整中提升标准化作用

中国电器工业协会标准化工作委员会于2009年5月上旬,召开了会员大会暨电工标准化工作会议,结合国家经济形势和行业具体情况,探讨研究标准化工作服务产业调整振兴的方向、目标,部署工作重点。     

Electrical injury: understanding the body's response

Studies of electrical injury are described in which the electrical field associated with the current is shown to be a source of damage, in addition to heat. It is shown that this result explains clinical observations that connective tissue is not harmed during electrical accidents, while skeletal muscles are destroyed. The researchers identified three cell categories, exhibiting three distinct types of response to the electric field     

夜间天津城市道路交会区户外LED显示屏照明现状调研及分析

随着城市建设的不断发展,户外LED显示屏作为广告新载体越来越多的得到运用。这种新型的广告载体,在夜间对城市道路交会区交通极易产生干扰。本文以天津市区为例,针对道路交会区这一特殊的空间,对夜间户外LED屏的现状进行实地调研,以期对户外LED显示屏的现状有一个初步的了解,对今后在城市道路交会区如何更科学合理地使用这种广告载体,减少其对交通干扰提供一定的参考依据。     

Web/spl I.bar/Soc: a Socratic-dialectic-based collaborative tutoring system on the World Wide Web

A Web/spl I.bar/Soc tutoring system for recursion concept learning is proposed. The system integrates different modes of learning, synchronous and asynchronous, collaborative and individualized, into a World Wide Web (WWW) environment. The paper proposes a collaborative learning protocol. Based on the protocol, the principles of the Socratic dialogue are applied to the collaborative learning of recursion concepts. In order to evaluate the effects on learning of the Web/spl I.bar/Soc system, an educational experiment was conducted. The results show that the effects from the Web/spl I.bar/Soc system were more obvious than merely studying articles.     

Building design: impact on the lighting control system for adaylighting strategy

The unique features of a multistory office building that successfully permit most of the space to be daylighted and the electric lights to be dimmed by a cost-effective centralized system are discussed. This system includes the use of light shelves, sloped ceilings, and proper building orientation and symmetry, and supplies only the ambient illumination. Measurements of the daylight illumination levels and the performance of the lighting control system indicate that daylighting can provide over 70% of the required ambient illumination through the year. Based on the installed cost of the lighting control system, its payback is 2.2 years     

新输电线路设计规范对杆塔设计的影响性分析

2020年国家电网基建部发布了一系列电网工程设计建设的技术标准,为探讨新规范对杆塔的影响,首先对输电线路工程影响较大的如电气、荷载等设计规范进行了分析,阐述其修订要点;接着对原杆塔通用设计采用数理统计分析方法,给出新规范对杆塔的影响.结果表明,本次输电线路相关规范的修订,对低电压等级的线路杆塔影响较大,无论是在电气间隙...     

OPGW标准化设计研究思路

OPGW已经得到越来越广泛的应用,但其产品设计、制造一直因工程线路参数而异,没有形成标准,OPGW产品间无互换性,给OPGW的检修、备品储备、集中采购带来不便。通过对OPGW在实际工程中所出现的诸多问题进行研究,总结出一套合理实用的OPGW设计思路与原则,并提出适应我国输电线路情况的OPGW标准化型谱,以指导工程设计选型。文章主要从OPGW标准化设计思路方面进行阐述,探讨在工程设计中如何对OPGW参数及选型提出要求,确立了一种以OPGW截面积为系列,自成体系、参数与地线配合的OPGW设计思路,并说明其合理性、可行性以及在OPGW标准化设计方面的重要性。     

OPGW防振方案设计初探

论述了光缆振动的理论和现今通行采用的防振方法，对使用单位和施工单位具有一定的指导作用。     

FSS设计中栅瓣现象的研究

栅瓣现象是影响频率选择表面（FSS）性能的重要因素,良好的FSS设计需要在工作频段内尽量避开或削弱栅瓣效应产生的影响。首先从电磁波传播的角度阐述了栅瓣现象产生的原因和条件。然后,依据周期结构的Floquet定理,总结了栅瓣与高阶Floquet可传播模式之问的联系,并且给出了Floquet模式的物理意义。同时针对厚壁波导型FSS结构进行仿真分析,研究其阵列周期及单元排布方式等因素对栅瓣的影响,并对大角度入射条件下的FSS设计提出了有价值的建议。     

Ventilator management: the role of knowledge-based technology

The authors discuss the problems associated with introducing an intelligent measurement and information system into a clinical high-dependency environment (HDE), typified by the intensive care unit (ICU) and postoperative recovery room. One specific situation in which intelligent instrumentation is required is during mechanical ventilation. A novel methodology that provides a structure for the incorporation of a knowledge-based component into the measurement process has been proposed. This methodology covers the entire development process, from a particular measurement system to evaluation of the final product. Specification and implementation for a prototype system designed for those patients who require ventilatory therapy as part of their overall management strategy has been developed using this methodology. This system is known as AIRS (Artificial Intelligent Respirator System)     

Market power and trading strategies on the electricity market: a market design view

In this paper, we examine auction-based electricity markets from the viewpoint of a power company in order to evaluate the market design. Optimal trading strategies under uncertainty are developed by abolishing the widespread assumption that a single company has no influence on the market price. The resulting trading strategies explain the high prices and the high volatility observed in real electricity auction markets and show to what extent power companies can manipulate the market price. From these trading strategies, we derive critical points in market design and formulate necessary and sufficient conditions that characterize a competitive electricity auction market. Unfortunately, these conditions are far from being realizable in practice, from which follows that electricity auction markets cannot be competitive.     

System grounding and ground-fault protection in the petrochemical industry: a need for a better understanding

This paper provides an in-depth discussion of system grounding and ground fault protection on systems from 480 V and above. The paper also discusses modeling of ground faults, the proper design for ground-fault protection, and common problems associated with ground-fault protection. The paper address many real-life problems associated with system grounding and ground-fault protection, including safety issues and how to avoid those problems. The topics included in the paper include low-voltage systems, under 600 V, through high-voltage transmission systems.     

基于DDS的信号模拟器设计

通过对DDS的信号模拟器设计的研究,不仅设计出能够实现普通射频合成信号源的功能,正如能够在幅度、频率等方面对所需生成的信号加以控制,也能够实现定频、扫频以及跳频等输出方式上的选择。同时,该系统增加了叠加噪声和灵敏度设置,以便能够更好地实现对各种条件下雷达回波信号的模拟。     

浅谈旋转对称灯罩的设计

利用光学软件Photopia设计旋转对称灯罩与其产品成型后的配光曲线图、平面等照度曲线及照度均匀性的效果图比较,探讨旋转灯罩在设计、生产和表面处理等相关问题。     

对变电站同期系统设计的探讨

分析现阶段变电站同期系统的任务 ,介绍了目前市场上同期装置产品的功能和特点 ,结合目前变电站同期系统设计中出现的问题 ,提出了今后变电站 (特别是枢纽变电站 )同期系统设计的理想模式     

变电所接地设计问题探讨

对接地电阻的要求值进行分析,提出了接地设计中常见的问题及解决措施。     

基于FPGA的图像采集系统的设计

研究一种基于FPGA和CMOS图像传感器的图像采集处理系统的实现方案。FPGA芯片的I/O口模拟SCCB串线总线写CMOS传感器中的寄存器,来设置CMOS图像传感器的工作方式,然后FPGA根据同步信号采集有效原始图像数据,在FPGA内还原出传统数字RGB格式图像数据,接着以帧为单位将图像数据转存到外部存储器SDRAM中,最后通过UART串口将图像数据转发到PC,进行实时处理或显示。所设计的采集系统能够正常工作,介绍的设计方案可靠有效。     

无人值守变电站的设计思路探讨

通过调研和工程设计的实践 ,阐述了经济型自动化系统和综合自动化系统的原理、特点 ,提出了当今城农网建设改造中无人值守变电站的设计思路 ,指出了设计分层分布式综合自动化系统的无人值守变电站是建设高度可靠、有效可控的现代化变电站的发展趋势