Results 1 to 10 of about 13,430 (151)

断路器容性电流开断能力研究

open access: greenGaoya dianqi, 2022
容性电流开断能力,特别是C2级开断能力,已成为断路器满足工程需求的关键指标,因开断过程中易发生重击穿故障而导致试验失败的风险较大,故需对其容性开断能力进行评估。基于容性电流特点,文中采用“恢复电压”及“最小临界电压”评估其开断容性电流能力,且“恢复该电压”低于“最小临界电压”时,断路器具有开断容性电流的能力。采用电场及气流场耦合分析方法,断路器开断性能进行评估,得到试验工况下“恢复电压”均小于“最小临界电压”,表明该断路器具有容性电流开断能力,顺利通过C2级试验验证,进一步表明采用“最小临界电压 ...
郭自豪   +8 more
doaj   +1 more source

基于KEMA电弧模型的SF6断路器直流分量开断能力研究

open access: greenGaoya dianqi, 2020
电力系统短路电流中直流分量的衰减时间常数超过现有断路器的标准时间常数将导致断路器实际开断能力下降,因此亟需研究直流分量对高压断路器的影响以准确评估其开断能力,防止开断失败造成重大损失。文中提出基于KEMA电弧模型研究SF6断路器直流分量开断能力的方法。首先,将KEMA模型引入直流分量开断仿真中,给出额定开断能力对应的临界电弧参数获取方法,然后使用临界参数仿真实际含更高直流分量的短路电流,最后用该方法验证宁夏电网断路器的实际开断能力。研究结果表明,当断路器的额定开断能力包含20%的直流分量时 ...
丁培   +6 more
doaj   +1 more source

考虑燃弧区间的断路器非对称开断能力校核方法研究

open access: greenGaoya dianqi, 2023
电网X/R比值增大会导致短路电流直流分量衰减时间常数超出在运断路器标准时间常数或特殊工况时间常数,在电力系统短路电流高直流分量影响下,断路器开断性能受限且无法达到标称的额定开断能力。文中综合考虑非对称短路电流开断过程中断路器燃弧窗口、电弧能量、电流变化率和电压变化率等因素对开断性能的影响,比对不同类型的断路器短路电流开断性能等效折算方法,提出考虑断路器修正系数的基于燃弧区间的非对称短路电流开断能力校核方法,并以电网实际系统的变电站短路电流情况进行实例校核验证 ...
马飞越   +5 more
doaj   +1 more source

420kV及以上高压断路器电寿命试验中SF6气体分解产物及其影响研究

open access: yesGaoya dianqi, 2023
断路器承担着切除电力系统短路故障的重要任务,当故障出现时,需要断路器在数十毫秒内开断短路电流,因此断路器的性能对电力系统的安全运行有着重要的影响。SF6气体是高电压等级交流断路器中最常用的灭弧介质,开断短路电流的过程中,SF6会在电弧作用下产生多种分解产物,降低断路器的开断能力。文中通过对5台420 k V及以上高压交流断路器开展电寿命试验,对SF6分解产物进行跟踪测量及分析,研究了SO2等分解产物对断路器开断性能的影响。
王昊   +7 more
doaj  

Biodiversity‐driven spatial conservation planning to delineate temporally stable regions

open access: yesConservation Biology, EarlyView.
Abstract The accelerating loss of biodiversity underscores the critical need for effective conservation strategies, particularly in the face of climate change and anthropogenic pressures. We devised a conservation planning framework that adopts a temporal stacking approach to species distribution models and landscape connectivity analyses. These models
Mattia Iannella   +5 more
wiley   +1 more source

Securing Bangladesh's Nuclear Future: Is the Regulated Asset Base Model the Answer to Address Project Corruption?

open access: yesJournal of Critical Infrastructure Policy, Volume 7, Issue 1, Spring/Summer 2026.
ABSTRACT Bangladesh's goal of achieving high‐income status by 2041 requires dependable, low‐emission, and affordable energy. With near‐universal grid coverage and increasing demand, nuclear energy is a strategic asset for long‐term baseload supply. However, the existing financing model, typified by the country's most expensive $12.65 billion Rooppur ...
Hafiz Ahmed
wiley   +1 more source

Nitrogen Anchoring Effect Triggering Improved Reversible Hydrogen Storage of Mg(BH4)2

open access: yesRare Metals, Volume 45, Issue 1, January 2026.
ABSTRACT This research uncovered the influence of nitrogen‐doped MXene Ti3CN on the reversible hydrogen storage properties of Mg(BH4)2. The Mg(BH4)2‐20Ti3CN composite began releasing hydrogen at a temperature of 80°C. In addition, the composite discharged over 8.8 wt% hydrogen at a comparatively lower temperature of 270°C, whereas the pure Mg(BH4)2 ...
Zhen‐Xuan Ma   +7 more
wiley   +1 more source

Constructing Serrated Boride Composite Layer for Enhancing Wear Resistance of Ti6Al4V Alloy

open access: yesRare Metals, Volume 45, Issue 1, January 2026.
ABSTRACT Appropriate configuration combined with strong interface bonding is the essential requirement for developing high wear‐resistant coatings. Herein, based on the powder‐pack boriding process, the properties of Ti6Al4V alloy are effectively improved by constructing a serrate tribological boride composite layer.
Ying Wu   +9 more
wiley   +1 more source

Achieving Superior Mechanical Properties for Al‐Zn‐Mg‐Cu Alloy by Coupling Design of Powder Press‐Forming, Deformation, and Aging

open access: yesRare Metals, Volume 45, Issue 1, January 2026.
ABSTRACT Enhancing the strength of 7000 series high‐strength Al alloys remains a critical challenge to meet the demands of increasingly demanding service environments. In this study, a novel approach is proposed for developing high‐performance Al alloys through a combination of powder mechanical alloying, powder press‐forming, rolling deformation, and ...
Peng‐Fei Ji   +4 more
wiley   +1 more source

Robust metrics for quantifying and comparing resistance and recovery in experimental studies

open access: yesMethods in Ecology and Evolution, Volume 17, Issue 1, Page 6-14, January 2026.
Abstract Various indices have been developed to experimentally quantify resistance and recovery (two components of engineering resilience) in response to anthropogenic and natural disturbances. This diversity complicates the selection of appropriate metrics for comparing resilience across ecosystems and studies.
Zewei Zhuang   +2 more
wiley   +1 more source

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