10kV配电线路保护的整定计算

10kV配电线路结构特点是一致性差,如有的为用户专线,只接带一、二个用户,类似于输电线路;有的呈放射状,几十台甚至上百台变压器T接于同一条线路的各个分支上;有的线路短到几百m,有的线路长到几十km;有的线路由35kV变电所出线,有的线路由110kV变电所出线;有的线路上的配电变压器很小,最大不过100kVA,有的线路上却有几千kVA的变压器:有的线路属于最末级保护,有的线路上设有开关站或有用户变电所等.     

腾飞的千里马——佳木斯千里集团董事长车千里创业写实

<正>从普通家庭的穷苦孩子——到拥有上亿元资产的著名私营企业家;从只有几台微机和几十人的培训班——发展到拥有五百多台先进微机、大屏幕媒体、电算化模拟实验室和4000多名师生的集幼儿、小学、中学、中专、大专为一体的全省乃至全国一流的综合性民办教育学团;从只有租赁几间教室——发展到拥有2．6万平方米6层现代化教学楼和     

探讨地区110千伏线路正常与异常方式下保护整定原则

结合地区电网110千伏线路保护的几种运行方式(正常方式、T接用户、电磁合环、临时方式考虑反带)下,考虑保护的上下级配合关系,并对该保护的整定原则进行探讨。     

浅谈无线宽带技术方案

一、引言 1．1背景随着计算机网络技术的发展，接人技术也发生了翻天覆地的变化。在接人介质方面，从铜线介质接人到光纤介质接人，再到无线接人；在带宽方面，从“小猫”到xDSL，从几Kbs到上百Kbs甚至几十上百Mbs，带宽越来越宽；从接入技术的两个分支——有线和无线来看，有线接人经历了以太网、FTTx（光纤到家、光纤到驻地）、FR（帧中继）、ATM；     

汕头出入境管理部门"科技+警力"高效办理

几十名市民坐着等候叫号,5台自助办证一体机排满了人,微信排队取号一个接一个……汕头市公安局出入境办证大厅一派火热景象.日前,记者采访中了解到,今年春节前后,汕头市出入境办证迎来"两头热",每天约有5000人次到全市各出入境办证大厅办证,出入境管理部门采取科技+警力积极应对办证高峰期,整个办证环境显得繁忙而有序.     

探讨电网输电线路工程导、地线的施工技术

根据《架空输电线路施工及验收规范》的规定,从实践中总结出线路工程的导、地线损伤处理,压接方式等几种施工方法。     

如何做好工商所的财务工作

一、基层工商所财务工作的重要性 工商行政管理工作是从70年代末开始的,随着经济的发展,改革开放的扩大,管理的面越来越宽,工作任务越来越重。从人员上说也大大增加了,一般工商所初始只有十来个人,现在有的大所已达到六、七十人,工商户由过去的几十个、几百个发展到几千个。各项收费也由开始的几万元,上升到现在的上百万元。工商行政管理事业的迅速发展,要求我们必须不断适应发展和变化     

电子表巧作曝光秒表

印放照片,需准确掌握曝光时间,市售的曝光定时器价格较贵。有的业余摄影爱好者在暗房操作时,因条件限制,用默记的方法计时,结果印放出的照片质量难以保证。如果用一块电子表,外加双刀双掷开关等少数元器件,按图中所示线路进行组装,即可成为一个廉价、实用的曝光秒表计时器。 打开电子表后盖,按图中所示,将开关左边的一端接电子表电池的“ ”极,开关的中间一端,接调整按钮的接触弹片上;开关的另一端接电源火线,开关的右边一端接插座;氖泡用日光灯启辉器里面的,将     

城镇化国际经验借鉴——新型城镇化建议之六

西方各国在历经几十年到上百年时间的发展后,在人类历史上率先实现了城镇化。其中,有的城镇是自然形成和发展的,有的是由政府的主动推动和促进而形成和发展的。总体来看,政府主动干预发展的城镇,在城市布局、城市建设、人文环境,生态环境和产业发展方面,普遍优于自然成长的城镇。     

关于进线备自投装置和线路保护装置的配合问题

通过现场调试人员的调试结果和用户反馈的情况,我们意识到大多接至线路保护操作回路的保护跳闸和保护合闸开入,是目前现场备自投装置的跳合闸出口的主要方式,由此带来的问题是备自投装置动作时会造成线路重合闸的不正确动作和不正确放电.     

常压燃气加热炉在小型油气田企业中的应用

我国小型油田和部分油田的边远井区在正常生产原油的同时普遍伴有天然气产出,同时国家现在重点开发的煤层气、页岩气、致密砂岩气等非常规能源在勘探研发阶段,其产气量大多在几百方至几千方每天,达不到商品化的规模,除部分用于生产加热外,大多直接排空或点火炬后排空[1]。小型油气田野外职工数量均在几十人到几百人之间,其采暖、制生活用热水及炊事用气总量在几十方至几千方每天,完全能自给自足。本文主要从适用、经济、安全方面入手,阐述常压燃气加热炉在小型油气田企业野外生活基地中采暖和制生活用热水方面的应用。     

Improving the voir dire process: A prospective juror's perspective

While the U.S. legal system takes pains to treat jury trial defendants fairly, it tends to treat prospective jurors unfairly, as if their time had little value. Citizens might view performing this important civic duty more favorably if the court made better use of their time. This article studies the voir dire phase of jury selection in California courts and investigates how it can be made more pleasant and productive from a prospective juror's perspective. A discrete-event computer simulation model of the process was built to test an alternative approach to handling jurors during voir dire, in which some are permitted to leave the courtroom and use their out-of-courtroom time as they wish, e.g., working or reading. Jurors can be recalled to the courtroom as needed via text messaging or paging, so the approach should be relatively easy to implement. Experiments performed with the model found that, depending on trial characteristics, jurors allowed to leave the courtroom would likely would recoup an average of one to 4 h, collectively recover dozens to hundreds of hours, comprising 15–30% of the total time spent by all jurors at the courthouse for voir dire, and potentially save several thousand dollars in lost income.     

Stochastic unpaced line design: Review and further experimental results

Previous design studies of unpaced assembly lines that exhibit stochastic task times indicate that an unbalanced allocation of task times results in optimal output rates. In this article, we present a comprehensive review of the previous literature on this topic and discuss the results of simulation experiments that test the bowl distribution for unbalancing unpaced lines. The simulation experiment was designed to test the bowl distribution in more realistic environments than previously tested and illustrates that a balanced line configuration is as good as or better than an unbalanced line configuration when task times are modeled with more typical values of variance.Stochastic unpaced assembly line research employs both simulation and analytical approaches to test the allocation of buffer capacity and task times to work stations. Analytical models are utilized to investigate simple line designs with exponential or Erlang task time distributions. Simulation is used for longer lines and for normal task time distributions. From the review of the previous research using both approaches, we note five major findings: 1) unbalancing task time allocation is optimal when task time variation is large; 2) unbalanced allocation of buffer storage capacity improves line output rate when task time variation is large; 3) output rate of an unpaced line decreases as the number of sequential workstations increases; 4) output rate increases as more buffer storage capacity is available; and 5) output rate decreases as the task time variation increases.Most of the previous research on unpaced lines investigated lines with few workstations and large task time variation. Empirical research by Dudley (6) suggests that variation of task times in practice is much less than variations employed in previous unpaced line studies. We present the results from simulation experiments that model longer unpaced lines with lower levels of task time variance of the magnitude that is likely to occur in practice.The results of our simulation experiments verify the benefits of using the bowl distribution for task time allocation when line lengths are short and task times experience large variance. However, when line lengths are extended or task time variation is reduced, the use of the bowl distribution for unbalancing the line degrades the line's efficiency. In these situations, the optimal task time allocation is a balanced line.Two important implications for managers follow from the results of our experiments: 1) that unpaced line output rate is relatively insensitive to moderate variations from optimal task time allocations when buffer storage is limited; and 2) that perfectly balanced line designs are optimal for most cases in practice.     

关于110kV线路避雷器故障的分析与探讨

在架空输电线路的运行过程中,有时会因为种种原因将部分线路改建为地下电缆。为解决电缆线路的防雷问题,需在电缆两终端安装线路避雷器,保护高压电缆和电缆头不受到线路过电压的损害。本文从110KV泸柏线线路避雷器爆炸断裂、终端连接导线被灼断这一事故,就110KV线路避雷器故障进行分析和探讨,并提出了防范类似故障的一些设想。     

数据快速压缩算法的研究以及C语言实现

压缩算法有很多种,但是对需要压缩到一定长度的简单的报文进行处理时,现有的算法不仅达不到目的,并且变得复杂,本文针对目前一些企业的需要,实现了对简单报文的压缩加密,此算法不仅可以快速对几十上百位的数据进行压缩,而且通过不断的优化,解决了由于各种情况引发的解密错误,在解密的过程中不会出现任何差错。     

Poverty Orderings

This paper reviews the literature of partial poverty orderings. Partial poverty orderings require unanimous poverty rankings for a class of poverty measures or a set of poverty lines. The need to consider multiple poverty measures and multiple poverty lines arises inevitably from the arbitrariness inherent in poverty comparisons. In the paper, we first survey the ordering conditions of various individual poverty measures for a range of poverty lines; for some measures necessary and sufficient conditions are identified while for others only some easily verifiable sufficient conditions are established. These ordering conditions are shown to have a close link with the stochastic dominance relations which are based on the comparisons of cumulative distribution functions. We then survey the ordering conditions for various classes of poverty measures with a single or a set of poverty lines; in all cases necessary and sufficient conditions are established. These conditions again rely on the stochastic dominance relations or their transformations. We also extend the relationship between poverty orderings and stochastic dominance to higher orders and explore the possibility and the conditions of increasing the power of poverty orderings beyond the second degree dominance condition.     

电法勘探电极多道遥控器的研制

在地面电法勘探工作中,利用无线电遥控代替跑极,可以节省人力或传输导线,降低成本。遥控发射机采取地址、数据综合变码的办法,用12键发射机就能控制40路通道,且易于扩展。一系列遥控接收机连接在每根电极与供电或测量导线之间,形成电极多通道遥控器。这种新型电极控制装置使用方便,换极速度快,能适应电阻率法和激电法等实用要求。     

Decomposing the operational efficiency of major cruise lines: A network data envelopment analysis approach in the presence of shared input and quasi-fixed input

To examine the top cruise lines' operational efficiency in three dimensions, namely, production, marketing, and profitability, this study adopts a network data envelopment analysis approach considering shared and quasi-fixed input factors. The empirical results reveal the following findings. First, the production process tends to outperform marketing and profitability processes. Second, inefficiency of a cruise line mostly stems from overconsumption of the exogenous inputs in each process and the shared input. Third, the relationships between operational efficiency of cruise lines and some categorical factors are examined. Finally, some managerial implications derived from the empirical results are formulated for cruise lines.     

谈城市110kV以下配电线路改造杆塔的选型和使用

城市老城区随着旧房改造和用电设备的增加,用电量不断增加,而原来供电线路的供电能力有限,因此经常出现线路过载造成开关跳闸和导线过热造成断线等故障.近年来,一些城市对老城区的旧线路和供电方式进行更新改造,但由于历史原因和客观条件的限制,无法采用电缆直埋的方式进行改造,需用架空明线的方式进行供电改造.     

广佛环线对珠三角地区城际轨道交通网通达性的影响

广佛环线属于轨道交通网络中圈层的几何范畴,为广佛都市圈的城际环线。该线连接了广佛地区重要的交通枢纽,并与珠三角地区城际轨道交通线网规划中8条城际轨道交通线路衔接,是珠三角地区城际轨道交通网"三环"中最为重要的"一环"。通过对广佛环线功能定位分析和通达性计算表明:该线不仅满足了沿线地区客流需求,推动了广佛同城化进程,同时还将以广州为中心的放射形线路紧密的组合在一起,提高了珠三角地区城际轨道交通线网的通达性,提升了线网服务效率。