基于直接反馈线性的永磁同化步电机直接转矩控制

文中应用一种基于直接反馈线性化（DFL）理论的非线性控制方法．通过对系统输出变量进行李微分,得到反馈线性化所需的坐标变换和非线性系统状态反馈．实现了永磁同步电机系统的输入输出线性化．并将原系统分解为两个线性子系统：转速线性子系统和励磁电流线性子系统,实现了系统的解耦。仿真结果表明：基于直接反馈线性化解耦的永磁同步电机直接转矩控制系统具有较好的速度跟踪性能并提高了系统对电流扰动的鲁棒性。     

基于SVM逆系统的五相永磁容错电机解耦控制

设计了一种应用于五相永磁容错电机的解耦控制器,实现了调速系统的线性化及解耦。该智能控制器采用支持向量机(SVM)逆系统理论结合构成SVM逆控制器,由SVM来逼近原系统的逆系统,将原系统解耦成两个伪线性子系统,通过两个PI控制器调节子系统的控制性能。SVM逆控制器集合了SVM方法的高精度跟踪与逆系统解耦的优点。仿真和实验结果表明,在FTPM电机运行时,当参数发生变化,SVM逆系统控制器依然能表现出很好的稳定性与精确的响应性。     

直驱永磁同步风力发电系统MPPT跟踪控制

根据永磁同步风力发电机的运行特性,构建以输出功率为反馈量、转速为控制对象的最大风能捕获控制模型,并在永磁同步发电机d,q轴数学模型和矢量控制理论基础上,通过转子磁场定向控制策略,实现有功、无功功率解耦控制,减小了损耗,并且较好地控制了转速。利用Matlab/Simulink进行仿真,对风速阶跃变化时机组运行情况进行了仿真,并给出了仿真结果。实验结果验证了该控制系统的正确性与可行性。     

基于PSCAD的双馈风力发电机组低电压穿越的研究

针对双馈风力发电机组低电压穿越问题,研究了电网电压严重跌落情况下转子Crowbar电路、转子Crowbar和直流侧卸荷电路组成的组合保护电路的控制策略。基于PSCAD建立了双馈风力发电机组低电压穿越的仿真模型,验证了组合保护电路控制策略能够很好地抑制转子侧电流和直流侧电压的上升,实现低电压穿越。     

四旋翼飞行器姿态的显式模型预测控制

针对四旋翼飞行系统的多变量、强耦合和带约束等复杂特性,提出了基于显式模型预测的控制方法。首先根据四旋翼飞行系统的动力学特点,建立了九状态空间模型,并解耦成2个子系统。然后,采用多参数二次规划法,离线计算了四旋翼飞行系统的显式最优控制律,在线查找当前状态对应的控制量。数值仿真和实验结果表明,该方法在满足约束条件同时,调节时间较短,超调量较小且具有一定的抗扰动能力,成功实现了四旋翼飞行器的姿态稳定控制。     

PID神经网络在飞控解耦中的仿真研究

在进行飞行控制律设计时,为了获得好的控制品质,有必要对各输出量进行解耦,并且使控制器能根据被控对象动力学特性的改变而自适应调整。为此,介绍了两种PID神经网络解耦控制结构和一种神经网络辨识器,并分别给出了PID神经网络解耦控制器和辨识器的前向算法及反向传播算法;最后分别应用两种解耦方法针对飞机横侧向线性模型进行计算仿真,得到了两种解耦结果;证明了PID神经网络解耦控制的有效性,并比较了两种结构的优缺点。     

BTT导弹自适应反演控制律设计与仿真

针对倾斜转弯(BTT)导弹控制中的多变量强耦合问题,研究了一种适用于BTT导弹的反演算法,以实现自动驾驶仪的自适应解耦控制。根据BTT导弹控制的基本特性,建立导弹的非线性控制模型,并将其转化为适合于反演设计的反馈块模型。在此模型上,基于反演的非线性控制系统综合设计方法,加入自适应神经网络逼近系统中存在的不确定性,利用Lyapunov稳定性定理推导了自适应调节律,设计了导弹控制律。通过仿真验证了该设计方法的有效性和可行性,该控制器能够实现控制解耦目的,且对指令信号跟踪效果良好。     

双馈风力发电机功率解耦控制的研究

介绍双馈风力发电机的基本原理,利用矢量控制并结合定子磁场定向的矢量控制,建立基于Matlab的双闭环控制系统仿真模型。为了更为准确地实现定子磁场定向并考虑到定子绕组电阻对磁场定向的影响,采用改进型的定予磁链观测模型。通过仿真验证了采用改进型定子磁场定向的双馈风力发电控制系统,实现了有功功率和无功功率解耦。     

直驱风力发电永磁同步电机矢量控制

本文以永磁直驱风力发电矢量控制系统为研究对象。在详细推导永磁发电机数学模型基础上,采用电流矢量解耦独立控制永磁发电机输出电流的有功和无功分量,实现无静差控制。同时通过最佳叶尖速比法最大风能跟踪方法,获得最大风能利用系数,实现系统的最大效率运行。仿真结果表明所采用控制策略的有效性。     

永磁直驱风力发电系统内模解耦控制研究

针对永磁直驱风力发电系统中传统解耦策略易受系统参数变化的影响、对负载变化的适应能力差和抗干扰能力弱等缺点,本文将内模解耦控制引入双三电平永磁直驱风力发电系统网侧和机侧控制系统,并对机侧内模控制器的设计进行了详细的介绍。仿真实验结果表明电流内环采用内模解耦控制后,可有效抑制干扰及模型失配对输出的影响,克服传统的PI控制不能动态解耦以及对电机参数敏感的问题,并增强对给定信号的跟踪能力。     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Nanoimprint Lithography -A Next Generation High Volume Lithography Technique

IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

Influence of PVK ： NPB hole transporting layer on the characteristics of organic light-emitting devices

A doping system consisting of NPB and PVK is employed as a composite hole transporting layer （CHTL）. By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK ： NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK ： NPB at 1：3.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.     

Analysis of error performance on Turbo coded FDPIM

Due to variable symbol length of digital pulse interval modulation（DPIM）, it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation（FDPIM） method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.