Results 41 to 50 of about 13,042 (158)
Gaoya dianqi, 2007 在分析现有各种小电流接地系统单相接地故障选线方法的基础上,对小电流接地系统单相接地故障的系统零序电压和线路零序电流的相轨迹特性进行了深入分析,提出了使用相轨迹方法来选线的原理。该方法计算简单方便,结果直观易懂,选线结果不受CT极性影响。该原理适用于中性点不接地系统和非有效接地系统,并在该系统发生间歇性接地故障时仍可保证正确选线,比其它方法容易实现。通过MATLAB环境不同条件下各种接地故障的仿真研究,验证了上述方法的正确性。
李功新
doaj
Dianci bileiqi, 2020 主要通过EMPT电磁暂态分析软件对10 kV串联间隙金属氧化物避雷器在配电网系统中安装使用时进行仿真分析,首先进行PS15绝缘子及10 kV环电极避雷器及穿刺避雷器产品的U50%放电电压试验,再仿真分析在不同接地条件下只安装单相产品对同级其它相绝缘子的影响及只安装一级对相邻级绝缘子的影响,分析得出无论是直接接地还是单独接地,当雷电流超过40 kA后均会造成相邻相或相邻级的绝缘子闪络,建议全线安装或在雷击严重区段及易击点全线安装10 kV串联间隙金属氧化物避雷器,不需单独设置接地,条件允许可在末端设置接地。
刘素芳, 陈康, 刘思贤
doaj
Design and Implementation of distribution network fault processing system [PDF]
, 2011 随着配电网络的迅速发展和客户对电能质量及供电服务的要求不断提高，实现配电网的自动化已成为电力系统发展的趋势。配电网作为输配电系统的最后一个环节，其实现自动化的程度与供用电的质量和可靠性密切相关。配网因其线路复杂，故障检测与定位一直是困扰检修工作的难题，人工检测耗时耗力，停电时间长，设备损害大。采用本文论述的配网故障处理可提高检测效率，缩短停电时间、减轻检修工作强度。并系统改变了国内同类系统只能检修人员到现场，通过故障指示器的翻牌信息进行故障判断的现状，系统的实现可成为配网自动化的重要组成部分 ...
刘卫斌
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Quantitative support for the benefits of proactive management for wildlife disease control
Conservation Biology, Volume 39, Issue 1, February 2025.Abstract Finding effective pathogen mitigation strategies is one of the biggest challenges humans face today. In the context of wildlife, emerging infectious diseases have repeatedly caused widespread host morbidity and population declines of numerous taxa.
Molly C. Bletz +2 more
wiley +1 more source
Dianci bileiqi, 2017 分析了城市中低压配网的接地拓扑结构,研究了10 kV配网中性点经小电阻接地后的380V侧接触电压隐患以及安全条件。针对单台区独立式和多台区互联式的台区接地方式,依据相关标准和典型设计分别建立场路模型,开展了台区单相接地故障时的接触电压安全性及影响因素仿真研究。结果表明:1)对于单台区独立式的台区接地方式,保护接地与工作接地的最小分开距离受接地电阻和重复接地影响;2)对于多台区互联式的台区接地方式,最小互联台数与台区间距离、重复接地密切相关。
雷潇, 廖文龙, 刘强, 李林欢
doaj
Ultrasound in Obstetrics &Gynecology, Volume 64, Issue 4, Page 470-479, October 2024.ABSTRACT Objectives Our aim was to examine the prenatal profiles of pregnancies affected by an atypical chromosomal aberration, focusing on pathogenic copy‐number variants (pCNVs). We also wanted to quantify the performance of combined first‐trimester screening (cFTS) and a second‐trimester anomaly scan in detecting these aberrations. Finally, we aimed
K. Gadsbøll +6 more
wiley +1 more source
The Application of Residual Current Protection Device in The Electrical Fire Prevention [PDF]
, 2014 剩余电流动作保护装置是防范电气火灾的有效方法之一。本文结合规范要求及系统原理对剩余电流动作保护装置在防范火灾中的应用做了几点阐述和总结。The residual current protection device is one of the effective methods to prevent electrical fires.This paper introduces some points and summarizes the application of residual current ...
张晓山
core
, 2020 从本质上介绍了不接地系统到电阻或消弧线圈接地系统的演变过程；引出了接地变和接地变兼站用变的概念，解释了接地变、接地变兼站用变的构造和原理；遵照国家标准，并借鉴项目经验，总结了通过接地变兼站用变铭牌参数确定短路阻抗选取基准侧的方法，并且结合实例给出了详细的解释推导，奠定了接地变兼站用变的短路电流计算，继电保护整定计算的计算基础；基于确定基准侧后的短路电流计算，分析了接地变兼站用变与普通接地变的速断保护整定计算的差异，分别从躲过变压器低压侧出口三相短路 ...
志磊 辛
core +1 more source
An integrated historical study on human–tiger interactions in China 中国人虎互动关系的综合性历史研究
Integrative Conservation, Volume 3, Issue 3, Page 183-195, September 2024.Tigers are important for maintaining a variety of life in the world as they are the top predators in the food chain. Human–wildlife conflict, including conflicts between humans and tigers, has been a global issue throughout history. This article focuses on human–tiger interactions in China, discussing various types of conflicts and measures for ...
Zhihong Cao +4 more
wiley +1 more source
Analysis on the Current Phase Compensation in Differential Protection for Transformer [PDF]
, 2013 分析了接线双绕组变压器微机差动保护相位补偿采用角接与算法相位补偿关系,变压器差动保护内部两相短路故障灵敏度与相位补偿关系,得出无论变压器中性点是否接地,相位补偿选择低压侧的方案对差动保护灵敏度有利。This paper analyzes the relationship between angle-connection phase compensation and the algorithm phase compensation using in the current phase ...
朱文强, 谢珍贵, 黄兴平
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