Results 11 to 20 of about 13,039 (119)

主变空载合闸引起的电缆护层过电压分析

open access: yesGaoya dianqi, 2019
变压器空载合闸过程中由于电磁振荡产生过电压,若系统中存在高压电缆,电缆内部过电压耦合到电缆护层造成护层上电压较高,护层过电压与电缆布置方式和护层接地方式有关。文中针对白莲河抽水蓄能电站主变空载合闸时,电缆端部有异常放电声,并可见放电火花的现象,对主变空载合闸时系统产生的过电压进行测量,并对放电现象进行观测;同时采用ATP/EMTP软件计算空载合闸过电压耦合到电缆护层上的过电压大小。测量结果表明:空载合闸时主变侧过电压值并不大,进而计算得到放电处护层过电压最大值为21.49 kV,频率在600 kHz以内,
张才军   +6 more
doaj  

Divergent Electrochemical Behaviors of O2 and O3 Phases in Li‐Rich Layered Oxides

open access: yesRare Metals, Volume 45, Issue 8, August 2026.
ABSTRACT Lithium‐ion batteries (LIBs) have dominated the landscape of electrochemical energy storage for decades. The growing market demands for higher energy densities are pushing against the limitations of conventional cathode materials. Li‐rich layered oxides (LLOs) present a promising path forward by harnessing both cationic and anionic redox ...
Juncheng Huang   +9 more
wiley   +1 more source

High‐Throughput Development of Advanced Metallic Glasses via Compositionally Graded Thin‐Film Combinatorial Strategy

open access: yesRare Metals, Volume 45, Issue 8, August 2026.
ABSTRACT Advanced metallic glasses, leveraging their ultrahigh strength, excellent corrosion resistance, superior soft magnetic properties and good biocompatibility, have gradually become indispensable strategic cornerstones in critical fields such as aerospace, electronic information and energy power. This unique combination of properties enables them
Yizhou Liu   +11 more
wiley   +1 more source

126kV真空断路器过电压仿真和保护技术研究

open access: yesGaoya dianqi, 2017
为保证126 kV单断口真空断路器挂网运行和操作过电压测试的安全,进行了断路器的操作过电压仿真计算和过电压保护研究。首先,确定断路器运行方式和建模数据;然后,EMTP建模仿真计算切合变压器和空载线路的操作过电压,并与变压器操作过电压的实际测试结果对比分析;最后,根据仿真计算提出过电压保护方案。结果表明,126 kV真空断路器的操作过电压较高,切空载变压器的过电压值低,不需要采取过电压保护措施,切负载变压器的过电压程度较高,应采取过电压保护措施,与现场测试结果一致;空载线路中由于110 ...
时振堂   +4 more
doaj  

Economic Security, Regional Reconfiguration, and Local Governance: The Case of TSMC's Investment in Kumamoto

open access: yesPolitics &Policy, Volume 54, Issue 4, August 2026.
ABSTRACT This study examines how institutional arrangements associated with economic security reshape semiconductor production in East Asia through the case of TSMC's investment in Kumamoto, Japan. It argues that economic security operates not primarily through direct administrative control, but by redefining acceptable investment risks, narrowing ...
Yumeng Wang
wiley   +1 more source

雷电过电压引发电容式电压互感器铁磁谐振特性分析与防护研究

open access: yesDianci bileiqi, 2019
近年来,电容电压互感器(CVT)在我国电力系统中得到越来越广泛的应用,需要详细研究雷电过电压引发CVT铁磁谐振特性及相应防护措施。通过在EMTP软件中建立35 kV变电站系统模型,分析线路遭受雷电直击或雷电感应时CVT铁磁谐振过电压特性,讨论过电压保护器件和阻尼装置等不同消谐措施的效果,最后分析线路安装避雷器或避雷线对铁磁谐振的抑制效果。研究结果表明:雷电过电压引发的CVT一次侧过电压波形振荡明显,雷电感应情况下过电压频谱范围更宽; CVT一次侧过电压幅值随着雷电流幅值的增加而增大 ...
郭亮   +7 more
doaj  

Between Dependence and Alienation: Understanding the Digital Minimalist Behavior of Chinese Millennials—An Analysis Based on SEM and fsQCA

open access: yesJournal of Adolescence, Volume 98, Issue 5, Page 1715-1736, July 2026.
ABSTRACT Introduction Following rapid iterations in media technologies, Chinese millennials (born between 1980 and 1995) find themselves in a paradoxical state where digital saturation exists alongside fatigue, making them central practitioners of digital minimalist behavior.
Chao Zhang, Yinze Hao, Jingwen Li
wiley   +1 more source

智能电表雷电感应过电压防护分析

open access: yesDianci bileiqi, 2018
智能电表的广泛应用伴随着严重的雷电灾害威胁,需要对智能电表雷电感应过电压防护进行详细分析。利用ATP软件搭建配电系统模型,编程计算线路雷电感应过电压,分析雷击点距线路距离和回击速度对智能电表终端过电压的影响,讨论安装线路避雷器、变压器低压侧避雷器、末端SPD的防护效果。分析结果表明:10 kV线路附近发生雷击时,感应过电压传递至智能电表终端时幅值仍然较高,50 kA雷电流幅值下终端过电压超过IV类设备冲击耐受电压;智能电表终端过电压随着雷击点距线路垂直距离的增加、回击速度的减小而降低 ...
王兆军   +6 more
doaj  

Wafer‐Scale Amorphous g‐C3N4 With Broadly Tunable Dielectric Properties for 2D Electronics

open access: yesRare Metals, Volume 45, Issue 7, July 2026.
ABSTRACT Two‐dimensional (2D) semiconductors are regarded as promising candidates for next‐generation electronics due to their superior electrostatic control; however, their performance is severely constrained by the lack of suitable dielectric materials.
Binyin Gao   +13 more
wiley   +1 more source

基于EMTP的电能表雷电浪涌过电压防护分析

open access: yesDianci bileiqi, 2018
随着电子式电能表的广泛应用,其受到的雷害威胁日益严重,迫切需要分析电能表雷电浪涌过电压以对其进行合理防护。利用EMTP软件建立简化的配电系统模型,计算电能表遭受的雷电浪涌过电压,讨论配电避雷器安装方式对电能表终端浪涌过电压的影响,研究电能表前端安装SPD的防护效果,最后分析柱上变压器距电能表不同距离和不同SPD接地电阻下电能表过电压。研究结果表明:流过电能表的电流和电能表的对地过电压波形均呈现较为明显的振荡,且波头时间较短。电能表的对地过电压幅值较高,极易超过其冲击耐受电压 ...
李霖, 曹彤, 荆臻
doaj  

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