Results 41 to 50 of about 34,473 (149)
基于振动信号EMD-HT时频分析的变压器有载分接开关故障诊断
Gaoya dianqi, 2012 把一列时间序列数据通过经验模态分解（empirical mode decomposition,EMD）为本征模态函数组（intrinsic mode function,IMF）,然后进行希尔伯特变换（hilbert transformation,HT）得到频谱的信号时频分析方法引用到变压器有载分接开关切换机构的振动信号分析领域。笔者介绍了该方法的理论和算法。首先采用仿真信号对该方法进行仿真验证,然后把一实测的有载分接开关故障振动信号进行基于EMD-HT方法的时频分析。通过仿真和实例信号分析结果说明 ...
张惠峰 +4 more
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Gaoya dianqi, 2021 为了及时有效地诊断变压器绕组松动故障,针对变压器空载合闸振动信号,提出了一种基于变分模态分解(VMD)的分析方法。首先运用VMD对绕组松动前后变压器表面合闸振动信号进行最优模态分解,建立信息熵—峭度—相关系数综合评价模型,并运用熵权—TOPSIS法提取特征模态分量;通过计算变压器振动信号能量熵进一步判定绕组状态;最后搭建测试平台进行实验验证。结果表明,绕组松动和正常状态下变压器振动信号在特征频率和能量分布上均存在明显差异,该方法为变压器绕组松动故障诊断提供了新的思路。
张九思 +4 more
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Magnetization Dynamics Control for Noise Reduction in Fluxgate Sensors
Rare Metals, Volume 45, Issue 8, August 2026.ABSTRACT Fluxgate sensors are indispensable for the detection of weak magnetic fields. However, their noise performance remains constrained by an incomplete understanding of the interplay between the high‐frequency magnetization dynamics of the core material and the overall sensor behavior.
Chunyang Mu +11 more
wiley +1 more source
Gaoya dianqi, 2014 为了满足经济效益与社会效益的需要,进一步加强变压器运行的安全性与稳定性,笔者提出了一种对变压器进行状态评估的方法。通过分析变压器运行中各状态量参数,引入基于关联规则的权重计算方法,采用综合分析与变权重评分制的方法,建立起一个较为完善的变压器状态评估体系,以更为准确地评判变压器运行状态的真实工况。实例分析证明,此方法能够为变压器实施状态检修提供有效的参考意见。
谢荣斌 +4 more
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Rare Metals, Volume 45, Issue 8, August 2026.ABSTRACT Gradient structures (GS) introduced by plastic deformation have been shown to effectively enhance the surface properties of metallic materials. However, the GS fabricated by existing methods often suffers from limited hardening depth and limited control over the GS layer, which constrain their engineering applications.
Yansong Guo +5 more
wiley +1 more source
Gaoya dianqi, 2011 为准确判断电力变压器故障后的绕组变形情况,笔者探究了频响法、短路阻抗法和绕组电容法综合判断变压器绕组变形的依据和规律。通过对故障变压器的理论分析和计算,结合实际的吊罩结果,证实了此3种方法的有机结合有助于准确分析和判断变压器绕组变形程度。
陈巧勇, 任红, 罗平, 王建强
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A class of montonicity-preserving subdivision scheme(一类矩形域上生成保单调面的细分法)
Zhejiang Daxue xuebao. Lixue ban, 2003 离散细分法是构造曲线曲面的一类重要方法,而在实际中某些细分法要求是保形的,即初始控制点是单调的,那么细分最终生成的曲线或曲面也要求是单调的.本文用构造法构造了一类在等距离意义下矩形域上生成线性保单调曲面的细分法,该细分法具有插值性、局部性、线性不变性,齐次性和仿射不变性,并用数学归纳法证明了该类细分法的保单调性、收敛性和光滑性.
LILi(李黎), PANZhi-geng(潘志庚)
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Rare 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
Sexuality, Gender &Policy, Volume 9, Issue 3, August 2026.ABSTRACT This article examines transmasculine pregnancy as a critical lens through which to analyze the intersections of cisnormativity, reproductive governance, and reproductive citizenship within healthcare systems. While existing research has documented barriers faced by transgender populations, less attention has been paid to how institutional and ...
Letícia Carolina Boffi +1 more
wiley +1 more source
Gaoya dianqi, 2011 在设计阶段准确计算并改善串级试验变压器的各级电压分布,对于合理地设计串级试验变压器具有十分重要的意义。笔者针对一台2250kV绝缘筒式串级试验变压器,根据变压器的绕组结构和外部尺寸利用有限元分析软件分别计算出变压器的内部和外部的电容参数,并将变压器外部电容采用等电位分配的方法归算为变压器级间电容。运用分配负载电容的方法建立变压器电压分布计算的等值电路,采用ATP-EMTP进行仿真计算,获得变压器的稳态电压分布。在变压器不满足电压分布要求的情况下 ...
顾朝敏 +4 more
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