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Optimized Bi-level Control for Day-ahead and Real-time Active Power Balancing of an Off-grid Wind Power-to-hydrogen System With ESS Considering Wind Power Uncertainty

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Dianwang Jishu/Power System Technology 2025年第1期49卷 52-62页

作者： Qiu, Yiwei Sun, Qingjie Wu, chenxu zhu, Jie Zeng, Yangjun chen, Shi Zhou, Buxiang College of Electrical Engineering Sichuan University Sichuan Province Chengdu 610065 China State Grid Ningbo Power Supply Company Zhejiang Province Ningbo 315012 China

Since off-grid wind power-to-hydrogen (Wp2H) systems are not connected to the utility grid, the hydrogen production load and the energy storage system (ESS) must be coordinated to absorb wind power fluctuations and maintain system stability. Such coordination must consider the flexibility constraints of hydrogen production units, the overall hydrogen yield, and the degradation of batteries in the ESS to meet the economic goals of green hydrogen production. Therefore, an optimized bi-level control method for the active power balance is proposed. Firstly, using the Itô process to characterize wind power fluctuations and considering the real-time flexibility reserve of multiple electrolyzers, the upper level is formulated as an intra-day scheduling problem with a 15-minute resolution. Secondly, the lower level optimizes the real-time power of the electrolyzers and the ESS based on their on-off states and baseline power commanded by the upper level, considering the degradation cost of the ESS. This helps to absorb second-level wind power fluctuations. Finally, based on a project plan in Inner Mongolia, China, a case study verifies the effectiveness of the proposed method. © 2025 Power System Technology Press. All rights reserved.

关键词： Hydrogen storage

Experimental research on electrochemical machining of titanium alloy Ti60 for a blisk

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Chinese Journal of Aeronautics 2016年第1期29卷 274-282页

作者： chen Xuezhen Xu Zhengyang zhu Dong fang Zhongdong zhu Di College of Mechanical and Electrical Engineering Nanjing University of Aeronautics & Astronautics

Ti60 （Ti-5.6A1-4.8Sn2Zr-1Mo-0.35Si-0.7Nd） is a high-temperature titanium alloy that is now used for important components of aircraft engines. Electrochemical machining （ECM） is a promising technique that has several advantages, such as a high machining rate, and can be used on a wide range of difficult-to-process materials. In this paper, orthogonal experiments are conducted to investigate ECM of Ti60, with the aim of determining the influences of some electrochemical pro- cess parameters on the surface roughness. The most important parameter is found to be the frequency of the pulsed power supply. It is found that using suitably optimized parameters for ECM can greatly decrease the surface roughness ofa workpiece. A surface roughness of approximately 0.912 μm can be obtained with the following optimal parameters： NaC1 electrolyte concentration 13wt%, voltage 20 V, pulse frequency 0.4 kHz, duty cycle 0.3, temperature 23 ℃, and anode feed rate 0.5 mm/min. Furthermore, blisk blades have been successfully processed using these optimized parameters

关键词： Blisk Electrochemical machining(ECM) Surface roughness Titanium alloy Ti60

瀑布沟水电站尾水隧洞出口高边坡地震作用效应及稳定性

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东北水利水电 2005年第5期23卷 1-3,6,59页

作者：段斌何江达李莉陈方竹四川大学水利水电学院四川成都610065 四川省农田水利管理局四川成都610015

瀑布沟尾水隧洞出口高边坡稳定性问题突出。本文采用动力有限元分析方法,研究地震荷载作用下边坡的动力响应特性,揭示边坡在地震作用下的变形、速度、加速度与应力分布特性,以及对边坡稳定性的影响。

关键词：瀑布沟水电站高边坡地震作用稳定性

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水利水电工程概论课教改理论与实践探究

广东水利电力职业技术学院学报 2007年第2期5卷 31-33页

作者：韦未李燕丛柿桐陈方竹华南农业大学水利与土木工程学院广东广州510642

论述“水利水电工程概论”在水利水电工程专业教学中的地位,结合教学实践,阐述在该课教学中应注意的问题及解决办法。

关键词：水利水电工程概论教学研究

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岩体初始地应力场的灰色计算模型及应用

红水河 2005年第3期24卷 61-64页

作者：刘军何江达陈方竹段斌四川大学水利水电学院四川成都610065

结合灰色计算模型和岩体初始地应力场形成的特点,给出地应力场GM模型的建立方法和精度预测,并运用GM(0,3)模型对锦屏一级水电站坝址区地应力进行回归分析,计算结果表明,GM模型较传统边界位移调整法具有更佳的回归效果。

关键词：灰色计算模型地应力回归分析锦屏一级水电站

Complete bounded λ-hypersurfaces in the weighted volume-preserving mean curvature flow

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Science China Mathematics 2018年第5期61卷 929-942页

作者： Yecheng zhu Yi fang Qing chen Department of Mathematics University of Science and Technology of China Department of Applied Mathematics Anhui University of Technology

In this paper, we study the complete bounded λ-hypersurfaces in the weighted volume-preserving mean curvature flow. Firstly, we investigate the volume comparison theorem of complete bounded λ-hypersurfaces with |A|≤α and get some applications of the volume comparison theorem. Secondly, we consider the relation among λ, extrinsic radius k, intrinsic diameter d, and dimension n of the complete λ-hypersurface,and we obtain some estimates for the intrinsic diameter and the extrinsic radius. At last, we get some topological properties of the bounded λ-hypersurface with some natural and general restrictions.

关键词： volume comparison theorem topology second fundamental form ∞-Bakry-Emery Ricci tensor mean curvature flow

A new correction method for quasi-Keplerian orbits

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Research in Astronomy and Astrophysics 2020年第11期20卷 191-204页

作者： Yue chen Da-zhu Ma fang Xia Purple Mountain Observatory Chinese Academy of SciencesNanjing 210033China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China School of Information and Engineering Hubei Minzu UniversityEnshi 445000China

A pure two-body problem has seven integrals including the Kepler energy,the Laplace vector and the angular momentum ***,only five of them are *** the five independent integrals are preserved,the two other dependent integrals are naturally preserved from a theoretical viewpoint;but they may not necessarily be from a numerical computational *** of this,we use seven scale factors to adjust the integrated positions and velocities so that the adjusted solutions strictly satisfy the seven *** the existence of the two dependent integrals,we adopt the Newton iterative method combined with singular value decomposition to calculate these *** correction scheme can be applied to perturbed two-body and N-body problems in the solar *** this case,the seven quantities associated with each planet slowly vary with *** accurate values can be given to the seven slowly-varying quantities by integrating the integral invariant relations of these quantities and the equations of *** should be satisfied with the adjusted *** tests show that the new method can significantly reduce the rapid growth of numerical errors for all orbital elements.

关键词： Computational methods Computational astronomy planets and satellites dynamical

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有限元计算中模型选择对结果的影响

红水河 2007年第2期26卷 61-64,80页

作者：苏向震何江达陈方竹四川大学水利水电学院成都610065 华南农业大学广州510642

土的本构关系是岩土力学的核心问题,在有限元计算中不同本构模型的建立将得到不同的计算结果,作者通过某电站厂房基础开挖过程中不同本构模型得到的不同结果进行比较得出本构模型选择对计算结果的影响。

关键词：有限元 DuncanE-μ 弹塑性模型 Duncan-Chang E-B非线性模型选择

Catalytic activity of Cu/ZnO catalysts mediated by MgO promoter in hydrogenation of methyl acetate to ethanol

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Journal of Energy Chemistry 2021年第10期30卷 203-209,I0006页

作者： fang Zhang Zhiyang chen Xudong fang Hongchao Liu Yong Liu Wenliang zhu National Engineering Laboratory for Methanol to Olefins Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina Dalian National Laboratory for Clean Energy Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina University of Chinese Academy of Sciences Beijing 100049China

Hydrogenation of methyl acetate is a key step in ethanol synthesis from dimethyl ether carbonylation and Cu-based catalysts are widely *** report here that the hydrogenation activity of Cu/ZnO catalysts can be enhanced by the addition of MgO *** evolution of crystal phases during coprecipitation and the physicochemical properties of calcined and reduced catalysts by X-ray diffraction(XRD),thermogravimetric(TG)-mass spectrometry(MS),Brunauer-Emmett-Teller(BET),transmission electron microscopy(TEM),N_(2)O titration,in situ CO-Fourier transform infrared spectroscopy(FTIR)and H_(2)-temperature programmed reduction(H_(2)-TPR)reveal that the promoter effect likely lies in the presence of Mg^(2+).A proper amount of Mg^(2+)mediates the precipitation process of Cu and Zn,leading to preferable formation of aurichalcite(Cu_(x)Zn_(1-x))5(CO_(3))_(2)(OH)_(6) crystal phase and a small amount of basic carbonates such as hydrozincite Zn_(5)(CO_(3))_(2)(OH)_(6) and malachite Cu_(2) CO_(3)(OH)_(2).The presence of aurichalcite strengthens the interaction between Cu and Zn species,and thus enhances the dispersity of CuO species and helps generation of Cu^(+)species on reduced ***,the performance of Cu/ZnO catalysts exhibits an optimal dependence on the Mg loading,i.e.,17.5%.However,too much Mg^(2+)in the precipitation liquid prohibits formation of aurichalcite but enhances formation of basic nitrates,leading to a dramatically reduced hydrogenation *** findings may find applications for optimization of other Cu-based catalysts in a wider range of hydrogenation reactions.

关键词： Methyl acetate Hydrogenation Cu/ZnO catalyst MgO promoter Precursor effect Aurichalcite