Results 11 to 20 of about 395 (125)
Gaoya dianqi, 2012 笔者分析了利用架空线路作为电流、电压线测量接地网接地电阻的误差来源,指出了线路的架空地线未与地绝缘是产生测量误差的根本原因。通过建立数学模型研究了变电站接地电阻值、电流回路电阻值、杆塔接地电阻值、架空地线类型的改变对接地电阻测量误差的影响;指出接地装置对地电压测量偏差主要受架空地线的短接范围的影响。为了减小大电流法测量接地装置接地电阻的误差,应当令测试范围内架空地线对地绝缘或采取人工放线的方式。
刘玮, 聂葳, 陈智, 徐鹏
doaj +1 more source
Dianci bileiqi, 2012 分析了未断开接地装置和架空地线连接时接地电阻的测量误差来源,指出实际流经接地装置的电流小于电流测量值是产生测量误差的根本原因。通过建立数学模型研究了变电站接地电阻值、电流回路电阻值、杆塔接地电阻值、架空地线类型的改变对接地电阻测量误差的影响。为了减小大电流法测量接地装置接地电阻的误差,应当断开接地装置和架空地线的连接并令测试范围内杆塔的架空地线与地绝缘。
刘玮, 柳玉波, 刘洋海, 高建勋
doaj +1 more source
Gaoya dianqi, 2021 架空地线因其不存在负载电流(除了很小的感应电流外),在冬季冰冻雨雪天气下较输电导线更易产生覆冰现象。而为了达到防雷效果,架空地线必须经铁塔可靠接地,这与在通电融冰工况下需使其对地绝缘相矛盾。文中针对所提出的一种220 kV防雷防冰灾架空地线系统,在简介其拓扑结构与工作原理基础上,根据该架空地线电缆参数及假设的融冰场景,通过计算直流融冰电流、电压,确定直流融冰电源的额定输出容量,并对该直流融冰电源的全桥模块化多电平换流器等核心部件的结构参数、元器件选型等进行了分析计算 ...
崔建业 +4 more
doaj +1 more source
Gaoya dianqi, 2015 针对由不同型号地线组成的长距离架空地线融冰问题,提出了一种长距离多分段架空地线直流融冰方案。研究长距离多分段地线融冰中普通地线及OPGW光缆的接线方式。为满足地线融冰电流与实际需要的融冰电流保持一致,提出了一种地线设计融冰电流计算方法。最后结合桂林站直流融冰装置与黎桂线架空地线具体参数,设计了黎桂线多分段架空地线直流融冰方案,通过PSCAD/EMTDC软件仿真分析与黎桂线地线直流融冰方案的工程应用,证明了该融冰方案的合理性与有效性。
李晋伟 +4 more
doaj +1 more source
idopNetwork: A network tool to dissect spatial community ecology
Methods in Ecology and Evolution, Volume 14, Issue 9, Page 2272-2283, September 2023., 2023 Abstract Network models have been used as a tool to characterize internal workings of complex systems. The amount of topological and functional information extracted from a network depend on the method of network inference and the type of network data.
Ang Dong +4 more
wiley +1 more source
Conservation Biology, Volume 37, Issue 3, June 2023., 2023 Abstract Many species are restricted to a marginal or suboptimal fraction of their historical range due to anthropogenic impacts, making it hard to interpret their ecological preferences from modern‐day data alone. However, inferring past ecological states is limited by the availability of robust data and biases in historical archives, posing a ...
Tom B. Letessier +8 more
wiley +1 more source
Using expert knowledge to support Endangered Species Act decision‐making for data‐deficient species
Conservation Biology, Volume 35, Issue 5, Page 1627-1638, October 2021., 2021 Abstract Many questions relevant to conservation decision‐making are characterized by extreme uncertainty due to lack of empirical data and complexity of the underlying ecologic processes, leading to a rapid increase in the use of structured protocols to elicit expert knowledge.
Daniel B. Fitzgerald +11 more
wiley +1 more source
, 2018 建筑信息模型(BIM)在土木建筑行业的应用得到了广泛关注,相关技术在工程实践中迅速发展与推广。智能化的BIM模型未来可能会逐渐替代传统图纸文件,建筑行业各方将更多采用BIM技术,朝着无纸化的方向发展。为了更好地保障结构在施工建设和运营管理期间的安全性,实现BIM模型向结构分析模型的自动转换,拓展模型的结构受力分析功能显得尤为重要。目前,某些有限元分析软件已开发相关模型转换接口,但若是针对复杂结构的精细化分析,则存在较多困难,往往还需要重新建模。本文基于C ...
吴焜, 陈志为, 黄锰钢, 黄颖
core +1 more source
, 2022 光纤复合架空地线(OPGW)在运行中受到内外条件的影响，结构中的金属绞线、油膏、光单元管和光纤等部分将发生一定程度的性能退化，导致光缆整体的健康度恶化。如何根据不同的参量对OPGW光缆的健康度状态进行评估，在故障发生之前进行维修或更换，是当下面临的主要问题。文章提出了基于主客观权重赋值法和主成份分析(PCA)法的OPGW光缆健康度评估方法，并进行了算例分析。数据分析结果表明 ...
侯继勇, 冯学斌, 武健
core +1 more source
Time-domain Analysis of Multiconductor Transmission Lines Excited by Transient Electromagnetic Disturbances Based on the Analog Behavior Modeling [PDF]
, 2020 L'abstract è presente nell'allegato / the abstract is in the ...
DU, ZIWEIHUA
core