Results 11 to 20 of about 13,145 (215)

Research on Lightning Performance and Protective Measures of ±800 kV UHVDC Power Transmission Line [PDF]

open access: yes, 2023
[Introduction] Lightning strike is the primary cause of failures of ±800 kV UHVDC power transmission lines, and the lightning protection assessment of power transmission lines is critical to the safe and stable operation of the system.
Youjun GONG, Zhiwen HE, Ziwei YAN
core   +1 more source

高压断路器切除并联电抗器过电压的抑制研究

open access: yesGaoya dianqi, 2021
高压断路器切除并联电抗器时会产生较高的过电压,而导致设备故障,危及电网安全运行。文中从开断电抗器产生过电压的原理出发,并结合试验结果分析过电压的区间分类,提出了重燃窗口以及过电压临界点的划分方法,详细分析了选相分闸技术抑制过电压的原理,并通过试验验证其可有效控制过电压在较低水平,从而消除过高的过电压对电力设备的威胁。
陈杳伟, 史俊, 党德旺, 付杰
doaj  

Research on the Key Parameters and Device Capacity Decoupling Analysis of Full Bridge MMC DC Ice-Melting Device [PDF]

open access: yes, 2023
[Introduction] This article aims to study the issue of the melting capacity and reactive output capacity of the full bridge modular multi-level converter (MMC) type DC (Direct Current) melting ice device under different operating modes.
Rui HE, Xiaogang WU
core   +1 more source

Start-up strategy of proton exchange membrane fuel cells [PDF]

open access: yes, 2016
To shorten the residence time of the H2/O2 interface and restrict the start-up voltage of the stack during the start-up process of a proton exchange membrane fuel cell(PEMFC),the effect differences of direct start-up,hydrogen purging time and auxiliary ...
LI Lun   +3 more
core   +1 more source

Optimal design of a new step-down 18-pulse autotransformer [PDF]

open access: yes, 2017
Aiming at the requirement for voltage regulation with a 18-pulse autotransformer-rectifier, a novel step-down 18-pulse topology was designed and optimized based on the advantage of present topologies.
GE Hong-juan   +3 more
core   +1 more source

考虑雷电过电压的风电机组拓扑结构优化

open access: yesDianci bileiqi, 2021
风力发电机遭受雷击时,塔筒内控制电缆、塔基处以及箱式变压器低/高压侧都会出现过电压,且过电压还会通过集电电缆和联合接地装置传到其他风电机组。为研究雷击风电场时引起的暂态电压,建立了包含风力发电机、集电电缆、箱式变压器的等效模型。考虑了雷电流参数、风力发电机接地电阻大小及风电场拓扑结构对风电场过电压影响。结果表明:单台风电机组遭受雷击的情况下,风电机组过电压值与雷电流幅值成正比,且波前时间为8.0μs和20.0μs时,雷电流幅值对控制电缆缆芯过电压影响很小;风电机组过电压值与波前时间成反比 ...
罗永志   +5 more
doaj  

Systematic Study of Fermi‐Level Pinning at Crystalline Metal/GaN Interfaces: First‐Principles Calculations and Diode Characterization

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT The Schottky barrier height (SBH), which serves as a pivotal determinant of charge carrier injection efficiency in electronic devices, critically governs electrical behavior at metal/semiconductor interfaces. However, pronounced metal‐induced gap states at metal contact interfaces induce Fermi‐level pinning, which constrains the ...
Xiaofei Liu   +10 more
wiley   +1 more source

Advanced NPs catalysts prepared by Nanoparticles Beam Composite Deposition System [PDF]

open access: yes, 2016
当前社会的发展对能源,尤其是对化石能源的需求日益扩大。化石能源作为一种不可再生资源供需缺口逐渐增大,而且其在利用过程中常伴随着严重的环境污染问题。燃料电池和氢能源作为一种新型绿色能源引起了人们越来越多的重视,具有长远的应用前景和重要的研究意义。直接甲酸燃料电池和电解析氢作为其中关键技术,已得到了大量的关注和长足的发展。目前采用的Pt及Pt基纳米催化剂存在造价高,活性低和寿命短等诸多问题,严重阻碍着燃料电池和氢能源的全面商业化运作。 本文采用课题组自主研发的纳米粒子束流复合沉积系统 ...
林城伟
core  

3D‐Printed Porous High‐Entropy Alloy Boosts Peroxymonosulfate Activation for Long‐Term Organic Pollutant Degradation

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT High‐entropy alloys (HEAs) have attracted considerable interest from researchers owing to their tunable chemical compositions, exceptional structural stability, and promising catalytic properties. However, their large‐scale application is often hindered by complex manufacturing techniques and poor durability.
Sheng Guo   +9 more
wiley   +1 more source

10 kV配电线路雷电感应过电压在线监测装置及其应用

open access: yesGaoya dianqi, 2023
雷电感应过电压是引起配电网故障的主要因素之一。为收集配电线路上的感应雷过电压数据,研究其波形特性,以期用于指导架空配电线路的雷电防护,文中采用了一个自供电、无线传输的雷电过电压在线监测装置,接触测量了配电线路中雷电感应过电压信号。通过对某10 kV配电线路上雷电感应过电压波形进行观测,并根据波形特征获取过电压相关波形参数。结果显示,感应雷过电压主要以高频分量形式叠加至工频相电压,所观察到的感应雷过电压波表现为波头时间短、波尾出现双极性高频振荡,最终衰减到零的特点 ...
徐文华   +7 more
doaj  

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