考虑风机一次调频的风电高占比电网机组组合

随着风电大规模、高渗透率接入电网,单纯常规机组一次调频已难以满足系统调频需求,迫切需要风电参与一次调频。文中在风机调频控制研究的基础上,提出一种考虑风机参与系统一次调频的机组组合模型。该模型通过加入稳态频率、频率最低点和频率变化率为约束条件,确保含风电电力系统预留足够的备用容量以支撑一次调频。文中采用大M法将非线性模型转化为混合整数线性规划模型,并调用Matlab中CPLEX程序包求解。最后,在IEEE 39节点系统上验证了该模型的有效性。仿真结果表明,该模型能提升系统承受负荷扰动的能力,从而满足更大负荷扰动下系统一次调频的备用需求。     

基于Infomap算法的配电网边缘划分方法

在能源互联网时代,配电网面临着海量分布式数据的计算和存储需求,而边缘计算可以利用网络末端资源就近提供配用电分析和计算,从而减轻主站计算、存储压力.为了充分发挥配电网边缘计算的优势以及提高配电网精细化运行管理水平,文章提出了一种基于Infomap算法的配电网边缘划分方法.首先,考虑配电网边缘规模和自治需求,明确定义配电网...     

安装误差对双圆弧齿轮啮合特性影响分析

为深入研究安装误差对双圆弧齿轮副啮合特性的影响,基于有限元法建立齿轮加载分析模型,研究啮合过程中单齿凸、凹齿廓的接触性能,对比分析安装误差对接触性能以及传动误差的影响规律。结果表明：啮合周期内,双圆弧齿轮的凹齿廓先接触且承担较大的法向接触力,但凸齿廓的啮入端接触应力最大,凸、凹齿面接触压力差与转矩成正比;安装误差对齿面接触性能影响较大,其中中心距误差容易引起齿轮分阶处应力集中,轴线平面的安装误差会引起齿面接触偏载,且对安装误差影响最大。     

Calculation of Static Suspension Depth and Meniscus Shape of a Solid Spherical Inclusion at the Steel–Slag Interface

Metallurgical and Materials Transactions B - A method to calculate the meniscus shape around an inclusion on the steel–slag interface is presented. The meniscus shape is related to the...     

冻融与氯盐侵蚀耦合作用下GO-RAC的耐久性能

通过混凝土抗冻性快冻法试验，研究了氧化石墨烯再生粗骨料混凝土（GO-RAC）在冻融循环与氯盐侵蚀耦合作用下的耐久性能，测试分析了GO-RAC的相对动弹性模量、质量损失率、抗压强度及氯离子侵蚀情况.结果表明：冻融循环与氯盐侵蚀的耦合作用加速了再生粗骨料混凝土（RAC）的劣化损伤，经历72次冻融循环后不同GO掺量GO-RAC的相对动弹性模量均降至其初始值的60%以下，宏观劣化程度较普通RAC有不同程度的降低；由于耦合初期侵蚀产物的填充致密效应，GO-RAC的抗压强度呈现先增大后减小的趋势；GO-RAC在冻融循环与氯盐侵蚀耦合作用下的Cl⁻分布符合Fick第二定律，表面的Cl⁻质量比随着耦合次数的增加呈指数形式增大，扩散系数随着耦合次数的增加先减小后增大.     

防脱冰相间间隔棒施工新工艺研究

导线不均匀覆冰和不同期脱冰会使线路发生跳跃,导致相间短路[1]。防脱冰改造施工中新型相间间隔棒可以有效地抑制脱冰跳跃。文中主要介绍了防脱冰改造施工中新型相间间隔棒的施工新工艺,运用此施工新工艺可以有效缩短停电施工改造时间,且对类似工程技术改进具有一定的参考价值。     

Mechanism of CeO_2 synthesized by thermal decomposition of Ce-MOF and its performance of benzene catalytic combustion

In this paper,the formation mechanism of mesoporous CeO_2 synthesized by thermal decomposition of Ce-MOF and its performance of benzene catalytic combustion,as well as the structure-activity relationship between them were studied in depth.The self-assembly process and physicochemical properties of CeO_2 were characterized by thermogravimetry analysis,powder X-ray diffraction,N_2 adsorption/desorption,high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy techniques.Characterization results show that Ce-MOF is completely decomposed into pure mesoporous CeO_2 when the decomposition temperature is higher than 400℃.At this threshold temperature,CeO_2(400) has the largest specific surface area and pore volume of 114 m~2/g and 0.152 cm3/g,respectively.CeO_2(400) exhibits very high catalytic activity for benzene combustion,which can completely catalyze the degradation of benzene at 260℃.Meanwhile,the mesoporous CeO_2(400) supported Pt nanocrystalline catalysts were prepared by high temperature solution-phase reduction method.Pt/CeO_2(400)can completely degrade benzene at about 200℃ and represents high durability and good waterresistance for benzene combustion during 100 h of continuous reaction.     

Thermoplastic polyurethane/polypropylene blends based on novel vane extruder: A study of morphology and mechanical properties

Thermoplastic polyurethane (TPU) polypropylene (PP) blends of different weight ratios were prepared with a self‐made vane extruder (VE), which generates global dynamic elongational flow, and a traditional twin‐screw extruder (TSE), which generates shear flow. The mechanical properties, phase morphology, thermal behavior, and spherulite size of the blends were investigated to compare the different processing techniques. Samples prepared with a VE had superior mechanical properties than the samples prepared with a TSE. Scanning emission micrographs show that the fiber morphology of the TPU/PP blends (<60 wt% TPU) was improved by elongational flow in VE. Differential scanning calorimetry curves indicate that a dynamical elongational flow could improve the miscibility of the TPU/PP blends. The U‐shaped spherulite size curve indicates the changes in the spherulite size, as observed from a polarization microscope. Interlocked spherulites also reveal the apparent partial miscibility of the TPU/PP blends under elongational flow. POLYM. ENG. SCI., 54:716–724, 2014. © 2013 Society of Plastics Engineers     

基于等代层模型的盾构法地层移动优化反分析

该文提出了盾构施工引起的地层移动的反分析优化方法,采用共轭梯度法优化程序并且基于等代层模型来评价地层移动,分析了回填注浆对地层移动的影响。通过南京地铁某盾构隧道监测数据的反分析结果,发现在粘土层中盾构施工对地表的影响角度大约为45°,回填注浆可以减少60%~80%的自然空隙。建立了新的经验公式来预测南京地区盾构施工引起的地层移动,实例表明该公式具有良好的效果。