Results 91 to 100 of about 30,964 (197)

110kV变压器中性点保护方式的探讨

open access: yesDianci bileiqi, 2001
介绍了中性点暂时过电压的几种形式 ;针对 1 1 0 k V薄绝缘变压器中性点不同的绝缘结构、不同的绝缘水平 ...
周威勇
doaj  

Review on position estimation methods to permanent magnet brushless servo motors [PDF]

open access: yes, 2016
2000-2001 > Academic research: refereed > Publication in refereed journalVersion of ...
Chen, YR, Cheung, NC, Wu, J
core  

The Essence of Crisis Decision‐Making: Saving Ravenna During the 2023 Floods

open access: yesRisk, Hazards &Crisis in Public Policy, Volume 17, Issue 2, June 2026.
ABSTRACT This article explores decision‐making processes in crisis situations by proposing an interpretive framework grounded in multiple criteria of rationality. Crises, characterized by uncertainty, urgency, and ethical dilemmas, require critical choices that go beyond standard procedures.
Alexandra D'Angelo, Federico Toth
wiley   +1 more source

按绝缘配合的原则选择变压器中性点保护与MOA参数

open access: yesDianci bileiqi, 1997
就110~220kV变压器中性点绝缘的过电压保护方式及避雷器的选择进行了详细的论述;重点探讨了高原、高海拔地区变压器中性点用避雷器的一些特点;并就云南省变电站中变压器中性点目前普遍采用的联合保护装置(避雷器和棒──律间隙)及避雷器选用的技术参数通过试验研究提出了个人的看法和建议。
何善庆
doaj  

可変速駆動システムの高効率化に関する国際標準化と対応技術の研究 [PDF]

open access: yes, 2020
明治大学博士(工学 ...
10210, 佐藤, 以久也
core  

A Global Analysis of Domestic Military Policies Governing Responses to Public Health Emergencies

open access: yesWorld Medical &Health Policy, Volume 18, Issue 2, June 2026.
ABSTRACT Throughout the COVID‐19 pandemic, militaries mobilized at an unprecedented scale to support domestic response efforts. This was consistent with the growing trend of asset mobilization for military operations other than war during public health emergencies.
Kuang Yu Hu   +4 more
wiley   +1 more source

基于空间矢量切换的三电平逆变器中性点电位平衡策略

open access: yesGaoya dianqi, 2009
中性点电位平衡问题是三电平逆变器在应用过程中需要考虑的一个重要问题,中性点电位不平衡不仅会增加功率开关器件的电压应力,并且在有源逆变的应用场合会造成逆变失败。首先建立三电平逆变器的数学模型,详细分析了空间矢量脉宽调制的特性和中性点电位失衡的原因,在此基础上研究了一种基于空间矢量切换技术的中性点电位平衡策略,根据实时直流电容电压和交流电流,通过正负小矢量进行等效切换完成对当前PWM信号的修正,从而实现中性点电位达到平衡状态,仿真结果验证了该方法的正确性。
石新春, 李光辉, 付超, 周国梁
doaj  

Geothermal characteristics and high-yield geothermal well parameters in the Baimiaozi sag of Huhe depression [PDF]

open access: yes
The geothermal geological conditions of Baimiaozi sag in Huhe depression are favorable for geothermal exploration. Previous geothermal investigations primarily focused on boreholes around the northern shallow-buried zone of the sag center, where the ...
Fugui YAN   +5 more
core   +1 more source

Gadolinium‐Induced Activation of CoNiO2 for Efficient Oxygen Evolution: A Structural and Electronic Modulation Approach

open access: yesRare Metals, Volume 45, Issue 5, May 2026.
ABSTRACT Multicomponent transition metal oxides (TMOs) incorporating rare‐earth (RE) elements have emerged as promising materials for the oxygen evolution reaction (OER). However, knowledge of how to regulate the structure of TMO‐based nanomaterials through RE incorporation to enhance catalytic performance remains limited.
Bolin Zhao   +6 more
wiley   +1 more source

中性点间隙击穿引起的220kV主变跳闸事故的分析

open access: yesDianci bileiqi, 2013
通过主变在雷电过电压下,中性点间隙击穿,零序保护跳开主变事故,说明间隙的放电分散性很大;提出220kV中性点不接地时,其保护必须是避雷器并联间隙后共用。论述了变压器在波过程中,中性点上的电压分布情况,指出二相进波或三相进波是保护装置动作的主要原因;论证变压器中性点与保护装置之间的绝缘配合问题,为减小间隙的击穿放电分散性,提出最简单和有效的办法是在间隙上方安放专用透明绝缘罩。
陈刚   +6 more
doaj  

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