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1.
配电网消弧线圈接地系统单相接地故障定位 实验研究   总被引:1,自引:0,他引:1  
针对配电网经消弧线圈接地系统单相接地故障定位困难的问题,该文分析了配电网经消弧线圈接地系统发生单相接地时零序电流特征量,提出了一种基于零序电流突变量和7次谐波选线技术的综合的配电网单相接地故障定位方法:在各线路出口及分支处安装馈线终端(FTU),独立测量零序电流突变量,并将FTU的单相接地定位结果与零序电流的7次谐波数据上送到配电网监控系统;配电网监控系统综合比较FTU的定位结果与各馈线零序电流的7次谐波数据,给出具体的故障定位流程和判据。实验结果证明该方法能正确、可靠地实现故障区段的定位。  相似文献   

2.
基于FTU的馈线故障定位矩阵算法研究   总被引:2,自引:2,他引:0  
为提高馈线自动化故障定位的准确性和时效性,总结了目前馈线自动化故障定位的几种应用模式,并分析了常用的故障定位矩阵算法的基本思想,在此基础上,依靠FTU(馈线终端单元)智能设备,提出了一种新的馈线故障定位矩阵算法,该算法采用有向边邻接矩阵来描述网络结构信息,通过多个矩阵的运算处理,可实现单电源树状网络、多电源开环运行网络以及馈线末端的故障准确定位。为验证算法的正确性,以一个多电源并列运行的复杂网络为例,在vs2008环境下采用C 语言编写了该定位算法程序,程序测试结果表明,该算法设计的正确、合理,能够实现馈线区段故障的准确定位。  相似文献   

3.
吴东菁 《广东科技》2014,(24):90-91
基于配网自动化的重要性,对配网自动化的故障定位技术研究进行探讨。首先对配网自动化的重要性进行阐述;结合现有配电网故障的检测方法,探讨了配网自动化中相关故障定位技术,主要包括开关设备故障定位技术和FTU故障定位技术,并对FTU的配电网故障定位算法及其研究概况进行介绍。  相似文献   

4.
基于馈线终端单元的馈线故障定位矩阵算法研究   总被引:1,自引:1,他引:0  
为提高馈线自动化故障定位的准确性和时效性,总结了目前馈线自动化故障定位的几种应用模式;并分析了常用的故障定位矩阵算法的基本思想。在此基础上,依靠FTU(馈线终端单元)智能设备,提出了一种新的馈线故障定位矩阵算法;该算法采用有向边邻接矩阵来描述网络结构信息,通过多个矩阵的运算处理,可实现单电源树状网络、多电源开环运行网络以及馈线末端的故障准确定位。为验证算法的正确性,以一个多电源并列运行的复杂网络为例,在vs2008环境下采用C++语言编写了该定位算法程序。程序测试结果表明,该算法设计的正确、合理,能够实现馈线区段故障的准确定位。  相似文献   

5.
结合我国配电网的实际情况,提出一种能够确定配电网故障点确切位置的实用方法.该方法通过比较各节点电压确定故障区段,并将故障区段始端故障电压与本线路末端短路时的故障电压对比得出故障点距离.该方法适用于中性点不直接接地系统的各种短路故障的定位,并可应用于故障的自动在线检测.  相似文献   

6.
一种配电网故障区段定位的改进矩阵算法   总被引:2,自引:2,他引:0  
唐华 《科学技术与工程》2014,14(11):196-199
分析了现有配电网故障定位矩阵算法存在的问题,提出一种配电网故障区段定位改进矩阵算法。该方法以网络关联矩阵描述馈线区段和测控点的拓扑联接关系,根据故障发生时与故障馈线区段相连测控点的故障过电流特征,形成一种适用于各类型馈线区段故障判定的统一判据。该算法判据形式统一、计算量小,省去了规格化处理与多次设定正方向的过程,能够解决环网故障、馈线末端故障、多电源网络多重故障定位等问题。  相似文献   

7.
配电网故障定位统一矩阵算法的改进   总被引:5,自引:0,他引:5  
文献[2]中提出了基于FTU的配电网故障定位的统一矩阵算法,但将该算法应用于辐射状馈线和树产太馈线的末端进行故障定位时,会无法判断出故障区域。在此提出在该算法中采用零编号的方法,结果表明该方法可以使得应用该算法对辐射状线跌末端和树状接线的末端进行故障定位时,不存在盲区。  相似文献   

8.
针对10kV电网节点多、分支多、传统故障定位方法不方便、不准确的特点,提出一种新的小电流接地下10 k V馈线单相接地故障定位方法。分析了发生小电流接地下10 k V馈线单相接地故障时线模电流暂态分量特性与相电流暂态分量特性。采用FTU检测装置进行故障信息采集,构建出相应的网络描述矩阵。通过控制平台对其进行处理得到故障判定矩阵,给出单相接地故障区段判定依据。实验结果表明,所提方法不但简便,还具有较高的抗干扰性和定位精度,能够有效地对小电流接地下10 k V馈线单相接地故障进行定位,为电网的安全稳定运行提供了强有力的保障。  相似文献   

9.
馈电线路发生故障时,故障区段必然位于两个相邻负荷开关之间的线路上,通过馈线终端单元采集故障信息上报SCADA系统,得到负荷开关上馈线终端的有关故障信息序列,利用故障信息进行故障区段定位。建立基于概率条件下的故障区段定位模型,利用发生故障时的最大故障概率这一条件进行故障区段定位,简单可靠。  相似文献   

10.
本文提出了以TI公司TMS320LF2407 DSP为核心处理器的馈线自动化远方智能终端(FTU)的设计方案,并根据FTU的硬件原理框图,设计了DSP基本外围电路,编写了FTU硬件电路的软件实现程序,实现了所设计的FTU的故障定位、故障隔离和供电恢复重要功能。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

16.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

17.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

18.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

19.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

20.
赵英华 《科技信息》2008,(12):219-220
0.Preface China has long been boasting of its colorful and immense culture which comprises of Taoism,Confucianism and Buddhism.The interwoven influence among the religions on Chinese way of thinking,on the nation's behavior in their social life throughout the long history is beyond list.  相似文献   

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