Results 21 to 30 of about 5,341 (112)
State estimation of power grid under smart grid integration based on FFCD-SOGI-PLL
Xibei Gongye Daxue Xuebao, 2022 在智能电网与新能源发电融合背景下, 电力电子接口装置的大量使用将给系统引入额外的直流偏置。因此, 电网电压信息获取算法的直流偏置抑制能力变得至关重要。二阶广义积分器锁相环(SOGI-PLL)广泛应用于电网信息的同步与提取, 可以有效抑制频率波动和相位跳变对电网状态估计精度的影响, 但其自适应频率反馈环节在实现谐波抑制的同时, 对于电网中含有的直流偏置非常敏感。针对这一问题, 提出了一种固定频率反馈的级联SOGI-PLL(FFCD-SOGI-PLL), 使用级联结构输入固定电网标称频率 ...
ZHOU Xiangyu +6 more
doaj +1 more source
Dianci bileiqi, 2022 为了掌握加装均流电阻对直流接地极运行性能的影响，为均流电阻装置的应用及运维提供参考，以水平圆环接地极为对象，分析了接地极加装均流电阻后的电气性能和温升性能变化，以及均流电阻阻值偏移对接地极电流分布和跨步电压的影响。结果表明：加装均流电阻可以使电流在各环段上的分配更均衡，相应的各极环附近最大跨步电压和温升更均衡，从而减小接地极的最大跨步电压和最大温升。均流电阻阻值偏移量越大，极环电流和最大跨步电压的变化量越大；当各极环均流电阻阻值的偏移量不均衡时，极环电流和最大跨步电压的变化量会进一步增加 ...
童雪芳, 谭波, 李元杰
doaj
There Is Always a Bigger Fish. Determinants of Power Perceptions in Swiss Biodiversity Policy
Policy Studies Journal, EarlyView.ABSTRACT The Advocacy Coalition Framework (ACF) views power as crucial in policy processes, but the nature of coalition power, its determinants, and how to empirically measure it remain understudied. In this article, we use a mixed method approach and social network analysis to explore power relationships in the biodiversity policy subsystem in ...
Alix d'Agostino +2 more
wiley +1 more source
Developmental 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
Rare Metals, Volume 45, Issue 5, May 2026.ABSTRACT Giga‐casting, a near‐net‐shape manufacturing process widely used in sectors such as new energy vehicles and aerospace, demands aluminum alloys with high integration, efficiency, and comprehensive performance. However, traditional die‐cast alloys still face two core bottlenecks: the strength–ductility trade‐off and high‐temperature ...
Zhanwei Su +3 more
wiley +1 more source
Gaoya dianqi, 2022 由于地磁暴在大地产生感应电流以及直流输电系统单极性运行方式与大地形成回路，使得直流电流进入变压器中性点，造成变压器直流偏磁，电流发生畸变，产生谐波。文中在已经研究过的单相特高压变压器直流偏磁计算的基础之上，以230 kV三相五柱式变压器为例，依据单相变压器和三相变压器电路、磁场的区别，利用变压器磁场模型与电路模型建立微分方程，对三相变压器的直流偏磁进行了计算分析。为使计算结果能够快速稳定，在电路中人为串联大电阻，并在计算完成后使用电压补偿的方法将串联电阻所分电压补偿在电路中，根据计算结果可知 ...
王泽忠, 郭苏鑫, 李冰, 张廉杰
doaj
Rare Metals, Volume 45, Issue 4, April 2026.ABSTRACT Photocatalytic hydrogen evolution technology is a crucial approach to achieve efficient solar energy conversion and green hydrogen production. However, traditional semiconductor photocatalysts often face issues such as weak visible‐light response, high photogenerated charge carrier recombination, and poor structural stability, severely ...
Longtao Guo +8 more
wiley +1 more source
Rare Metals, Volume 45, Issue 2, February 2026.ABSTRACT Photodetectors, based on GaAs nanowires (NWs), hold significant promise in the fields of high integration micro‐ and nano‐optoelectronics applications because of their outstanding electronic and optical properties. To date, significant efforts have been directed toward enhancing the performance of photodetectors, aiming for high detectivity ...
Yu Hao +11 more
wiley +1 more source
On the Damage Tolerance of Diffusion Bonded Titanium–Aluminum Phase Biomimetic Composites
Rare Metals, Volume 45, Issue 2, February 2026.ABSTRACT The biomimetic design principles of natural structures involve the strategic integration of stiff and compliant phases to synergistically enhance strength and toughness. Its evolutionary refined natural armor, characterized by a specialized microarchitecture, enables superior damage tolerance.
Shuai Tong +10 more
wiley +1 more source
Gaoya dianqi, 2023 为准确掌握直流偏磁下电力变压器铁心的振动特性，文中通过建立变压器电磁—结构多物理场耦合有限元分析模型，计算了变压器直流偏磁前后铁心磁通密度分布和励磁电流，分析了麦克斯韦力和磁致伸缩力作用下不同直流偏磁时的铁心振动特征，定义了S变换相对能谱熵来描述变压器铁心振动随直流偏磁程度的变化规律。对某500 kV三相五柱式自耦变压器的仿真计算结果表明，随着直流电流增加，变压器铁心振动幅值增大，振动频谱分量增多，但随后呈现饱和趋势，且铁心心柱和旁柱振动信号的S变换相对能谱熵变化各异 ...
宋奇珂, 王丰华
doaj