基于5G通信技术的配网架空线路故障自愈方案研究

为解决传统配网架空线路因没有配置保护引起跳闸或接地引起的故障无法有效实现自愈的问题，研究具有5G通信功能的配网智能开关保护配置及合理布局，可以达到配网故障快速自愈。在配网分线和主干线安装基于5G通信技术智能开关，配备电流和重合闸保护，并合理整定保护定值，与变电站出线保护有效配合，通过各智能开关终端的逻辑研判技术，实现快速隔离故障恢复非故障区域供电，从而减少停电用户数量，提升用户的用电满意度。某地区实际投入使用中，配网自动化自愈成功率明显提高，成功实现预期目标。     

基于模拟主站的配电终端信息就地快速联调技术

针对当前配电自动化系统中的配电终端与主站调试工作效率较低、标准化程度不高等问题,提出一种基于模拟主站的配电终端就地调试方法。通过在配电终端调试现场建立一个临时模拟主站,显示调度端所需要的各种信息,并且与实际运行主站进行同步,可快速地识别和隔离故障,解决了现场测试与主站必须建立通信的矛盾,同时减少了终端就地调试的时间,提高了配电自动化就地调试的效率。     

自动重合器必须与自动分段器配合使用

1　概述农村配电网自动化系统的主要功能 ,是在发生故障时将故障区段隔离 ,减少停电事故和故障时间 ,提高供电可靠性。而目前农村配电系统有的只装设柱上油断路器和跌落式熔断器 ,尚无其他保护设备。当配电网上发生永久性故障时大多依靠变电所出口重合器跳闸 ,造成整条线路断电 ,重合器仅起到具有重合功能的断路器作用 ,智能设备技术性能的优势远未发挥出来 ,只有在农村小型化户外变电所运用机电一体化功能的重合器和分段器相配合 ,形成有层次、有逻辑的递进保护 ,才能实现农村配电网的自动化。2　试运行情况东明变电所是一座农村小型化户外…     

V-I-T型自动分段器

该文介绍了一种新的配电系统自动网络重构方案--基于智能负荷开关的V-I-T自动分段器方案。V-I-T型自动分段器方案适用于环网或辐射型的架空和电缆线路,分段开关之间采用分布式智能V-I-T功能相互配合,无需通信网络,配合变电站出口断路器(重合器),自动完成故障定位、清除、隔离和转供,及时快速恢复供电,调试、维护简单方便,大大减少停电面积和停电时间。     

配电系统自动网络重构方案

介绍了一种新的配电系统自动网络重构方案—基于智能环网柜的V-I-T型自动重合器方案。V-I-T型自动重合器方案适用于环网或辐射线路,环网柜进线采用断路器,出线采用负荷开关或断路器,环网柜之间采用FTU智能自动化功能配合,无需通信网络,自动完成故障定位、清除、隔离和转供,调试、维护简单方便,不用变电站出口跳闸,大大减少停电面积和停电时间。     

判别中低压配电网故障区段的方法

结合配电网的特点以及供用电的综合信息,阐述了判别中低压配电网故障区段的基于智能开关、＂一遥＂、＂二遥＂、SCADA＂三遥＂、智能电能表终端、客户报修服务系统的5种故障区段判别方法。     

10 kV配电网智能断路器通用保护定值计算

<正>为减少10 kV配电网故障时的停电范围,提高供电可靠性,国网河南新安县供电公司2019年以来安装60台10 kV配电网智能断路器,取得了较好的效果。在实践中形成了一套10 kV配电网智能断路器通用保护定值计算方法,对保证配电网各层级保护级差合理匹配、降低线路变电站侧断路器故障跳闸率起到了良好作用。现简要介绍如下。1 10 kV配电网线路首端智能断路器保护定值计算     

浅谈配电网常用的馈线自动化模式

馈线自动化有2种实现方式：当地控制方式和远方控制方式。当地控制方式又叫电压型实现方式,通过重合器来实现。馈线失电压时开关设备跳开,然后依时间延时顺序试合分段开关设备,最后确定故障区段再隔离故障并恢复非故障区段供电。远方控制方式又叫电流型实现方式,通过负荷开关、FTU（馈线终端）和主站系统来实现。     

基于高速通讯的快速保护型配电自动化模式的研究

该文列举目前在国内配电自动化系统应用的几种基于保护原理的配电自动化模式:常规线路保护、面保护、快速光纤纵差保护,比较分析这些模式的优缺点及其在配电自动化系统中的适应场合。综合应用了面保护及电流型配电自动化的特点,提出一种基于快速光纤通讯集中处理保护的配电自动化方案,试验及应用证明此方案不需要配电站出口断路器跳闸,大大缩短了非故障线路的停电时间,并且动作准确可靠。     

重合器与分段器在配网自动化中的应用

配网自动化的一个重要工作就是配电线路自动化。当配电线路出现故障时，要进行快速判断，排除故障段，保证非故障段的正常运行，减少停电范围。重合器与跌落式分段器配合使用可以有效的隔离故障区段95％以上，既提高了供电的可靠性又提高了社会和经济效益，为配网自动化打下坚实的基础。     

化探样品中微量元素Ag、W、Mo、Sn、Bi、Cu、Pb、Zn、Ni、Co、Cr的水平撒料光谱定量分析

针对化探样品批量大,元素多,检出限低等特点,采用水平电极撒料法,对化探样中多种微量元素进行了光谱定量分析.将样品与缓冲剂1:1混匀,采用W-100光栅摄谱仪(光栅刻线1200条/毫米,二级光谱)进行水平撒样摄谱,谱板经暗室处理后,在东德GFE760μ测微光度计上用P标尺测光,以△P-logc绘制工作曲线,查出含量.本法采用了特制的撒样漏斗,改善了下料的均匀性,提高了分析精度;以Ge和Pd作内标消除工作条件变化对谱线强度的影响;同时还试选了SiO2:C:Na2SO4＝61:30:9的混合物作缓冲剂,提高了弧烧的稳定性,获得了较高的再现性.本文还采用了一种单元素线减光器对Ag3382.9进行减光,使Ag的测定上限由5×10-6提高到30×10-6.本法操作简便快速,成本较低,一次可测定Ag、W、Mo、Sn、Bi、Cu、Pb、Zn、Ni、Co、Cr等多种元素,检出限为Ag 0.03×10-6,W 0.5×10-6,Mo0.05×10-6,Sn 0.4×10-6,Pb 1×10-6,Zn 3×10-6,Cu 0.5×10-6,Bi 0.1×10-6,Ni 0.3×10-6,Co 0.3×10-6,Cr 1×10-6,基本上达到了化探普查找矿定量分析的要求.     

2010年世界健康食品展望

当前,中国粮油企业的生存与发展已与世界粮油经济的发展息息相关。无论是粮油企业全面亏损的2004年,还是粮油价格大起大落的2008年,世界其他各国粮油政策和价格的变化均对中国的粮油产业发展造成了很大的影响。全面了解国际粮油发展新动向、掌握世界粮油食品发展新方向,从宏观上为企业找到准确定位,是每位粮油企业家、每位粮油人都必须具备的。正所谓知己知彼,百战不殆,希望以下这些国际前沿信息能为您带来收获。     

王水消解法同时测定土壤中Cu,Zn,Ni,Cr,Pb,Cd的方法研究

为了快速、准确地检测土壤中多种重金属元素,建立一种王水消解同时测定土壤中Cu,Zn,Ni,Cr,Pb,Cd的方法.选取8种具有广泛代表性的土壤标准物质对王水消解法进行考察,结合土壤标准物质标准值,通过大量试验数据对该方法做出全面评价.     

冀、鲁、豫、苏、皖五省农机夏收跨区作业调研报告

农机跨区作业是我国农民自发进行的又一项伟大的制度创新,为促进我国农业机械化发展做出了重要的贡献.为此,采用问卷调查法、文献资料法和数理统计法,对冀、鲁、豫、苏、皖等省505户参与跨区作业的农机大户进行了问卷调查.以问卷数据为基础,分析了农机大户的自身特征和经营状况,并总结了影响跨农机大户参与跨区作业的主要因素,最后提出了相应的对策建议.     

安徽省砀山县丰产农机合作社:创新模式发展优势服务

砀山县丰产农机服务专业合作社位于安徽省宿州市砀山县朱楼镇朱楼村,成立于2015年5月13日。合作社目前占地1.33 hm^2(20余亩),拥有成员200余人,拖拉机40多台,收割机18台,灌溉机械14套,植保飞机80多架,烘干机6组,配套农具230多台(套),机械资产达到1 200余万元。     

肥城桃不同栽培模式调查、经济效益分析及建议

肥城桃是中国著名的地方名优特果品之一,与奉化玉露、深州蜜桃、阳山水蜜并称为“中国传统四大名桃”。近年来,肥城桃产业高质量发展成效明显,一些优良品种的引进和新型栽培技术的应用,极大推动了肥城桃的区域规模种植,肥城桃种植成为当地桃民增收的重要途径之一。本文就山东省肥城桃产业实践应用中的三种不同栽培种植模式的生产成本和经济效益进行调查、分析,提出发展建议,以期为肥城桃种植提质增效和高质量规划发展提供参考。     

Advection,evaporation, and surface resistance

Summary We study the effect of surface resistance r (whether of monolayers on free water or plant diffusive resistance) on evaporation rate, energy balance, and microclimate, under advective conditions. We use power-law representations of the vertical profiles of mean windspeed and eddy diffusivity, and exploit two known similarity solutions, one for a step-function change of surface concentration, and the other for a step-function change of surface flux density. To a very close approximation, these two contrasting canonical advective problems yield the same (spatially variable) boundary layer transfer coefficient expressing the ratio of the surface flux perturbation to the surface concentration perturbation. Adopting this coefficient reduces the (spatially variable) surface energy balance for the advective boundary layer with surface resistance to a quadratic equation, with the solution yielding the fetch distances x at which the surface temperature assumes a given value To. With To (x) established thus, the other significant properties of the boundary layer follow simply and directly.The results reveal the profound influence of r, especially at small x. As boundary layer atmospheric resistance increases with x, r becomes relatively less important. It can be regarded as primarily reducing advective effects. Antievaporation films thus work best on small water surfaces in arid surroundings, but are less effective the larger the water body and the moister the surrounds. If leaf temperatures are not limiting, increasing r has greatest effect for small vegetated areas in an arid environment, but may not be optimal for extensive continuous monocultures. Control of surface resistance offers means of manipulating microclimate, for example when arid landscapes are watered for this purpose. The exploratory nature of this investigation, and its many limitations, are stressed.     

The FARMSCAPE approach to decision support: farmers', advisers', researchers' monitoring,simulation, communication and performance evaluation

FARMSCAPE (Farmers', Advisers', Researchers', Monitoring, Simulation, Communication And Performance Evaluation) is a program of participatory research with the farming community of northeast Australia. It initially involved research to explore whether farmers and their advisers could gain benefit from tools such as soil characterisation and sampling, climate forecasts and, in particular, simulation modelling. Its current focus is facilitating the implementation of commercial delivery systems for these same tools in order to meet industry demand for their access. This paper presents the story of what was done over the past decade, it provides performance indicators of impact, it reflects on what was learnt over this period and it outlines where this research is likely to head in the future.Over the past 10 years, the FARMSCAPE team employed a Participatory Action Research approach to explore whether farmers could value simulation as a decision support tool for managing their farming system and if so, could it be delivered cost-effectively. Through farmer group engagement, on-farm trials, soil characterisation, monitoring of crops, soils and climate, and sessions to apply the APSIM systems simulator, FARMSCAPE represented a research program on decision support intervention. Initial scepticism by farmers and commercial consultants about the value of APSIM was addressed by testing its performance both against measured data from on-farm trials and against farmers' experiences with past commercial crops. Once this credibility check was passed, simulation sessions usually evolved into participants interactively inquiring of the model the consequence of alternative management options. These ‘What if’ questions using APSIM were contextualised using local climate and soil data and the farmer's actual or proposed management rules.The active participation of farmers and their advisers, and working in the context of their own farming operations, were the key ingredients in the design, implementation and interpretation of the FARMSCAPE approach to decision support. The attraction of the APSIM systems simulator to farmers contemplating change was that it allowed them to explore their own system in a manner equivalent to learning from experience. To achieve this, APSIM had to be credible and flexible. While direct engagement of farmers initially enabled only a limited number of beneficiaries, this approach generated a commercial market for timely and high quality interactions based on soil monitoring and simulation amongst a significant sector of the farming community. Current efforts are therefore focused on the training, support and accreditation of commercial agronomists in the application of the FARMSCAPE approach and tools.The FARMSCAPE approach to decision support has come to represent an approach to guiding science-based engagement with farm decision making which is being tested nationally and internationally.