PMSG风电系统最大风能捕获自适应模糊滑模控制器设计

在分析了永磁同步发电机数学模型的基础上,以实现额定风速下风能的最大捕获为目标,采用滑模控制和模糊控制相结合的方法,提出了一种新的自适应模糊切换控制方法。该方法使得风电系统在额定风速以下时,能够根据风速的变化实时地改变电机转速,从而获得最佳叶尖速比,实现最大功率追踪的目标。仿真结果表明,自适应模糊切换控制方法可以有效实现额定风速下的最大风能捕获,同时弥补非线性给系统带来的影响,提高了系统的鲁棒性和稳定性。     

Generator,multiquadric generator,quasi-interpolation and multiquadric quasi-interpolation

The aim of this survey paper is to propose a new concept “generator”. In fact, generator is a single function that can generate the basis as well as the whole function space. It is a more fundamental concept than basis. Various properties of generator are also discussed. Moreover, a special generator named multiquadric function is introduced. Based on the multiquadric generator, the multiquadric quasi-interpolation scheme is constructed, and furthermore, the properties of this kind of quasi-interpolation are discussed to show its better capacity and stability in approximating the high order derivatives.     

分级优化方法在复杂板梁结构中的应用：—水轮发电机上架体的优化设计

本文探讨分级优化方法在复杂板梁结构优化设计中应用的可行性及提高优化效率的途径。运用应变能相等的原理构造板梁结构的简化模型,达到实施分级优化。提高优化效率进而可以用较少的计算机资源解决较为复杂的工程问题的目的。通过运用数学规划技术并谨慎地选择各优化层次上的变量转换关系,达到加速整个优化过程的收敛。     

汽轮发电机定子端部线棒坐标及法向的数学模型

本文给出了汽轮发电机定子端部线棒坐标及法向的数学模型,为准确计算汽轮发电机端部漏磁场、线棒电磁力以及股线间的环流,提供了严格而有效的方法。     

Quantitative Mobility Spectrum Analysis for Determination of Electron and Magneto Transport Properties of Te-Doped GaSb

Resistivity, magnetoresistivity and Hall effect measurements in n-type Te-doped GaSb grown by the liquid encapsuled Czochralski technique are carried out as functions of temperature （35-350 K） and magnetic field （0-1.35 T）. The power law model is used to explain the temperature-dependent resistivity. The magnetic-field-dependent data are analysed using the quantitative mobility spectrum analysis technique. The effect of individual band parameters （nL, nr, μL, μr, p and μp） on both the electron and magneto transports have been discussed. The EL - Er energy separation between the L and conduction band edges is also derived.     

Magneto-Optic Coupling Theory for Guided Optical Waves and Magnetostatic Waves Using an Arbitrarily Tilted Bias Magnetic Field

We report the magneto-optic （MO） coupling interaction of guided optical waves （GOWs） with magnetostatic waves （MSWs） in MO film waveguides using arbitrarily tilted bias magnetic fields. The universal MO coupledmode equations are obtained and can be applied to the collinear or noncollinear interactions of the GOWs with magnetostatic forward volume wave （MSFVW）, magnetostatic backward volume wave （MSBVW） and magnetostatic surface wave （MSSW）. As a typical example, the noncollinear diffraction interaction of the GOW with the MSFVW excited by single-element microstrip line transducer in the yttrium-iron-garnet （YIG） film is analysed in detail. For the case of normal magnetization, the calculated plot is consistent with the experimental results in the first passband. By comparison, the diffraction efficiency （DE） can further be improved by optimizing the magnetization direction. The maximum DE gain can reach 5. 7 dB under the appropriately inclined bias magnetic field at φ = 180° and θ = 9°.     

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在现场完成发电机定子铁心叠片及紧压工作后,必须进行发电机定子铁心磁化试验以便检查铁心叠片是否有短路及螺栓是否压紧等。通过给缠绕在定子铁心上的励磁绕组通入交流电流,从而在铁心内部产生铁心损耗,使铁心发热,通过测量铁心各部温升根据试验标准判断铁心是否合格。由于300MVA脉冲发电机的工作频率是变化的而非常规的50Hz工频,因此通过计算获得了变频67Hz和99.6Hz下定子铁心的单位铁损耗。脉冲发电机的定子铁心磁化试验结果表明定子铁心装压质量及绝缘是合格的。试验结果为变频率工作的发电机的铁心磁化试验提供参考。     

Gr\"{o}bner-Shirshov Basis of Quantum Group of Type $\mathbb{D}_4$

The authors take all isomorphism classes of indecomposable representations as new generators, and obtain all skew-commutators between these generators by using the Ringel-Hall algebra method. Then they prove that the set of these skew-commutators is a Gröbner-Shirshov basis for quantum group of type \(\mathbb{D}_4\).     

大型风力发电机的发展新动向

风力发电占总发电量的比重不断提高,风力发电机的使用越来越广.随着大型发电机用各种材料性能的不断提高和改善,很多以前无法实现的电机设计理念得以变成现实.本文简述了目前占主导地位的常规永磁直驱和双馈风力发电机的优缺点;介绍了近期涌现的新型风力发电机:高压风力发电机,液压风力发电机,超导风力发电机,海上用风力发电机,无刷双馈风力发电机等,对于其原理和特点进行了说明;最后对大型风力发电机今后的发展方向进行了展望.