Results 1 to 10 of about 2,700 (116)

Research on lightning transient distribution characteristics of cable-stayed bridges [PDF]

open access: yes, 2023
Bridges are usually located at the junction of land and water, where the surrounding area is open terrain, making them to be easily damaged by lightning strikes.
Dajun XU   +4 more
core   +1 more source

Research on the Interaction Between Multi-Circuit Shared HVDC Grounding Electrodes [PDF]

open access: yes, 2023
[Introduction] Unlike the independent grounding electrode, shared earth electrode is connected to multiple DC (Direct Current) systems, and its parameters and operation mode need to be determined by each system connected to it.
Wen WANG, Yu LIU
core   +1 more source

Research on Thermosensitive Coatings for Thermal Runaway Warning in Energy Storage Power Station [PDF]

open access: yes, 2023
[Introduction] Lithium iron phosphate battery storage power plants are an important basis for new power systems to consume large-scale new energy, however, the thermal runaway of battery cells seriously threatens the operational safety of storage power ...
Chaolu NIU   +8 more
core   +1 more source

远海风电柔性直流送端交流系统故障协调控制 [PDF]

open access: yes, 2023
为提升远海风电对称双极柔性直流送端交流系统单相接地故障和两相短路故障工况(第一类故障)下的功率输送能力,以及三相接地故障工况(第二类故障)的交流电压稳定性,提出海上换流站协调控制策略。首先分析了第一类故障的过电压和极间环流产生机理,以及第二类故障的交流电压失稳机理。在此基础上,提出了功率平衡控制策略和输出有功电流策略。第一类故障下定电压控制极采用限压策略,功率平衡控制策略抑制极间环流,增大定电压控制极的功率,减少了交流电压控制器响应时间,提升了功率输送能力。第二类故障工况下 ...
叶荣   +4 more
core   +1 more source

基于双塔Transformer 的电力系统暂态稳定评估 [PDF]

open access: yes全球能源互联网
基于数据驱动的方法在电力系统暂态稳定评估的效率和精度提升上已经取得了一些研究成果。然而电力系统暂态过程中涉及多维度时序特征的变化,常规算法对特征的提取能力不足且缺乏可解释性,难以反映系统暂态过程中的动态行为。因此,构建了一个具有双塔结构的Transformer模型,以Transformer编码器作为特征提取器,考虑同一时刻不同维度的特征以及每一维度特征在不同时间步对系统暂态稳定的影响,并将其分别作为双塔结构Transformer模型的输入,训练和学习各特征通道和时间步对系统暂态稳定性的影响。通过融合机制,
赵晨浩   +4 more
doaj   +1 more source

International clinical practice recommendations on the definition, diagnosis, assessment, intervention, and psychosocial aspects of developmental coordination disorder – Chinese (Mandarin) translation

open access: yesDevelopmental Medicine &Child Neurology, Volume 61, Issue 3, Page E1-E35, March 2019., 2019
目的 本国际临床指南由欧洲残疾儿童学会(the European Academy of Childhood Disability,EACD)牵头制定,旨在解决发育性协调障碍(developmental coordination disorder,DCD)的定义、诊断、评估、干预以及与社会心理方面的临床应用关键问题。 方法 本指南针对五个领域的关键问题,通过文献综述和专家团队的正式讨论达成共识。为保证指南的循证基础,以“机制”、“评估”和“干预”为检索词, 对2012年更新以来提出的最新建议以及新增的“社会心理问题”和“青少年/成人”为检索词进行检索。根据牛津大学循证医学中心证据等级 (证据水平 [level of evidence, LOE]1–4) 将结果进行分类,最终转化为指南建议。并由国际 ...
Jing Hua   +6 more
wiley   +1 more source

差速器式双余度机电伺服系统的模式切换研究

open access: yes, 2022
研究了在一通道发生故障时,10 kW级差速器式双余度机电伺服系统的模式切换和故障重构过程。通过仿真对比了主-主工作模式和主-备工作模式时系统的暂态特性和频率特性参数;分析了主-主切换模式和主-备切换模式的正弦切换过程;并通过试验实现了在零位时和最大位移时的正弦切换曲线。仿真对比发现,与主-备工作模式相比,主-主工作模式的暂态特性和频率特性的参数更优;试验结果与仿真结果趋势一致,与在最大位移处的切换过程相比,在零位时切换的切换时间和振荡过程更长。因此,对于只有摩擦和惯量的被动负载的10 kW级机电伺服系统,
于志远   +4 more
core   +1 more source

Influence and its suppression of desired signal coupling to reference signal to interference cancellation system [PDF]

open access: yes, 2015
The time-domain characteristics of adaptive interference cancellation system with desired signal coupling to reference signal were analyzed.The analyses reveal the desired signal makes the system a time-variation system and the optimal weights were ...
Yun-hao JIANG, Zhi-hua ZHAO
core   +1 more source

Joint Simulation Study on Load Characteristics of Wind Turbines in Low Voltage Ride Through Process [PDF]

open access: yes
ObjectiveThe grid fault of voltage drop will cause severe variations to the load of wind turbines, and seriously affect the safe and stable operation of wind turbines.
LIANG Kai   +5 more
core   +1 more source

特高压GIS隔离开关开合母线方式3试验中暂态电压波形解析

open access: yesGaoya dianqi, 2023
为分析特高压GIS隔离开关方式3试验中暂态电压与断口间动态绝缘特性的关联,文中构建了超宽频暂态电压监测系统和电弧形态观测系统,全过程监测了特高压GIS隔离开关开合过程中电源和负载侧的暂态电压,以及动静触头间击穿时的电弧形态。试验发现,隔离开关方式3试验合闸和分闸过程中电弧重燃和熄灭交替出现的持续时间分别为140 ms和240 ms。电压峰值附近发生的电弧熄灭,将引发过电压,但幅值低于1.4 p.u.。分合闸过程中产生的暂态电压持续时间约12μs,波头时间约25 ns,其频率主要分布在1 MHz以下 ...
李敬雄   +7 more
doaj  

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