Results 1 to 10 of about 19,224 (119)
Nonlinear free vibration analysis of Timoshenko beams with porous functionally graded materials
Xibei Gongye Daxue Xuebao, 2022 基于Timoshenko梁变形理论研究多孔功能梯度材料梁的非线性自由振动问题。针对多孔功能梯度材料梁的孔隙均匀分布和孔隙线性分布2种形式, 根据广义Hamilton原理推导多孔功能梯度材料Timoshenko梁的非线性自由振动的控制微分方程组并对方程组进行无量纲化。采用微分变换法(DTM)对各种边界条件下的控制微分方程组进行变换, 得到等价代数特征方程。计算了多孔功能梯度材料Timoshenko梁在固支-固支(C-C)、固支-简支(C-S)、简支-简支(S-S)和固支-自由(C-F ...
TENG Zhaochun, MA Lingquan, FU Xiaohua
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基于DE-RBF 混合优化算法的微电网自适应下垂控制策略 [PDF]
全球能源互联网, 2023 孤岛微电网因线路阻抗各异，采用传统下垂控制无法实现功率按分布式电源容量比例分配，会产生电压/频率偏差。为此，提出一种基于DE-RBF混合优化算法的自适应下垂控制策略。首先，构建下垂控制的两逆变器并联微电网系统动态模型，应用差分进化 （differential evolution，DE） 算法获得多个平衡点的优化下垂控制参数。为提高系统的动态响应速度与稳定性，通过训练径向基 （radial basis function，RBF） 神经网络，对每个平衡点参数进行校正。进而，通过增加RBF神经网络的隐含层数量，
吴丽珍, 魏建平, 丁安邦, 陈伟
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Gaoya dianqi, 2022 文中设计了一种具有主动故障穿越能力的自治智能光伏（photovoltaic,PV）逆变器，所提逆变器具有有功功率和无功功率的解耦控制特性，它可以根据电网状态或电网运行员命令在预期的运行模式之间无缝切换。智能逆变器根据电网状态自动调整其有功和无功功率设定值，在正常电网和故障电网条件模式下分别以最大功率点跟踪（maximum power point tracking,MPPT）和低电压穿越（low voltage ride through,LVRT）模式运行。此外，文中还提出了一种新型自治模型预测控制 ...
何瑞, 谢振刚, 程昱舒
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Gaoya dianqi, 2023 为了解决光伏发电在电网电压跌落过程中，逆变器两侧功率不平衡出现过电流和过电压的问题，设计了一种定功率跟踪控制的光伏并网低电压穿越策略。通过定功率跟踪控制对光伏阵列输出功率进行调节，根据电压跌落深度，合理给定功率参考值，控制光伏阵列的功率输出，实现交、直流侧功率的快速平衡，限制直流母线电压的增长。通过逆变器无功补偿控制，不仅能限制并网电流在安全范围内，还能够根据跌落深度提供无功支撑，有效地利用了逆变器自身的无功调节能力。结果表明，该策略能够抑制过电压和过电流，使系统具备一定的低电压穿越能力。最后 ...
董广凯 +4 more
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Gaoya dianqi, 2022 针对电网电压出现不平衡会导致储能变流器（power conversion system,PCS）输出的有功功率波动、无功功率波动和三相电流峰值越限问题，文中提出了一种考虑电流峰值限制的储能变流器协调控制策略。首先分析了传统控制策略在电网电压不平衡下的局限性；其次利用瞬时功率理论与加权思想，在αβ两相静止坐标系上实现抑制有功功率波动与抑制无功功率波动的协调控制；然后在上述基础上，加入一种电流峰值限制方法，能在PCS进行协调控制的同时保障输出的三相电流峰值不越限 ...
谭丽平 +8 more
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Methods in Ecology and Evolution, EarlyView.Abstract DNA barcode‐based species identification has become pivotal in biodiversity research. Current barcoding‐based deep learning methods have advantages in species identification but exhibit significant limitations. By using COI barcoding alone, previous studies were unable to fully capture species identification features. Prior methods showed that
Bin Ye +4 more
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Laser‐Driven Halide Exchange and High‐Resolution Multicolor Patterning of Perovskite Films
Rare Metals, Volume 45, Issue 3, March 2026.ABSTRACT Translating the excellent properties of metal halide perovskites (MHPs) into practical flexible optoelectronic devices requires high‐resolution multicolor patterning techniques that are compatible with post‐fabrication processing. However, such a capability has remained elusive.
Shu Yang +6 more
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High‐Brightness Delayed Imaging Realized by Embedding Zinc Gallate Nanocrystals Into Glass
Rare Metals, Volume 45, Issue 3, March 2026.ABSTRACT X‐ray delayed imaging technology leverages an “irradiation‐storage‐thermally stimulated readout” mode, demonstrating unique advantages in intermittent monitoring scenarios such as high‐temperature/high‐radiation environments. This typically requires materials combining abundant carrier‐trapping energy levels with structural thermostability ...
Jun‐Xiao Wu +6 more
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Electrolyte With Functionalized Boron Nitride Nanosheets for Dendrite‐Free Lithium Metal Anodes
Rare Metals, Volume 45, Issue 3, March 2026.ABSTRACT Lithium metal batteries (LMBs) are regarded as promising candidates for the next‐generation high‐energy‐density storage systems due to their unparalleled theoretical energy density and low redox potential. However, the commercialization of LMBs is tremendously plagued by the barbaric growth of lithium dendrite and the intricate decomposition ...
Ji Zhou +5 more
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Gaoya dianqi, 2021 单芯电缆的结构参数和运行环境影响都会导致电缆的无功损耗变化。为了探究单芯电缆结构和运行环境对电缆无功损耗的影响,文中从电缆内部结构出发,建立了电缆等效电路模型。通过分析电缆内部无功损耗形式,研究了单芯电缆在特殊工况下的无功损耗变化情况。结果表明:单端接地电缆内部损耗以容性无功损耗为主;电缆电压等级越高时,输送一定功率的极限传输距离反而越短,并给出了66、110、220、330、500 kV电缆的极限传输距离;电缆内部进水后容性无功损耗会增大10%～30%,电压等级越高或者电缆截面积越大 ...
李瑞芳 +5 more
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