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由三菱电机开发研制的MELVEC矢量控制变频调速系统的装置中,采用了具有PWM高功率因数整流的控制技术,并且使用了IGBT、GTO、IGCT等功率器件。提高了功率因数,已被广泛地应用在钢铁(冶金)行业中。本文简要说明其电路构成的原理,重点介绍和分析了高功率因数的控制技术、控制系统的设计理念,并简述了装置中高次谐波的问题。 相似文献
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现阶段采用IGBT电压型高压变频器实现高压同步电机的速度及位置开环控制是很困难的。本文根据客户现场工况,提出了采用专用的JCS型IGBT高压变频器,实现高压同步电机拖动活塞式空压机的变频调速改造,取得了良好的运行效果和节能效果。 相似文献
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针对目前广泛使用的电机驱动运行过程中功率因数和效率较低及IGBT驱动电路复杂且保护功能不尽完善的问题,设计了一种基于驱动元件2QD30A17K—I和TMS320F2812高性能DSP的变频控制装置。采用恒压频比控制策略利用空间矢量PWM算法对电机输入电压和频率进行最优控制,从而实现完善驱动电路和提高电机的功率因数和效率的目的。本文完成了30kW变频器样机的制造及试验,试验结果表明在提高功率因数和效率方面达到显著效果,从而达到节能的目的。 相似文献
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基于DSP的异步电机SVPWM变频调速控制系统 总被引:1,自引:0,他引:1
阐述了变频调速控制和SVPWM的基本原理及实现方法,以TMS320LF2407为核心控制器,通过对硬件电路的设计和软件程序的编写,构建了一套基于DSP的异步电机变频调速控制系统。通过实验证明,该控制系统效果良好,能实现异步电机的变频调速,具有广阔的应用前景。 相似文献
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本文分析比较了高压变频调速与其它调速方式如定子调压调速,变极调速,液力耦合器调速的优缺点,介绍了IGBT直接串联高压变频器在煤矿皮带运输机上的应用,实现了宽范围调速,运行稳定可靠,对于煤矿行业变频器的设计与应用有很大的参考价值。 相似文献
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本文介绍了链条炉的定义,链条炉应用变频调速的意义,链条炉控制系统的原理,锅炉采用变频调速控制的优点,变频调速的控制方法和逻辑,链条炉采用变频调速装置的节能分析。 相似文献
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控制芯片在变频调速系统中有着非常重要的作用,针对变频调速系统的特点和封装集成、单片集成变频调速系统的要求,设计了一种适合于变频调速系统集成化控制芯片。该芯片主要采用数字电路实现变频调速控制策略,由于控制通过硬件数字电路实现,提高了控制电路系统的可靠性。针对目前采用单片机或DSP芯片控制时外围电路比较复杂的特点,引入了一种通信机制,实现了大多数的控制参数设置,在使用户具有较大的自由度的基础上,大大减少了控制IC的输入输出管脚,并在可编程逻辑器件FPGA上进行了实验验证,仿真和实验结果表明了该芯片具有较高的性能和便于集成化的特点。 相似文献
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为了解决风机、泵类的电机耗能过多的问题,提出了一种高压转子侧变频调速的节能方法.对高压转子侧变频调速系统的主回路拓扑结构进行了研究,报告了转子侧变频调速技术的国内外研究现状,阐述了通过改变绝缘栅极双极型晶体管(Insu Iated Gate Bjpo Iar Transistor.IGBT)占空比的方法,实现转子侧的变频调速,分析了主回路主要参数的计算公式.通过举例实际数据,验证了高压转子侧变频调速节能系统的良好性能,并且此系统有效地解决了能源浪费,转子侧变频调速造价昂贵、装置体积庞大等问题。 相似文献
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Michael Reilly 《半导体技术》2004,29(12)
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. 相似文献
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Thomas M.Trexler 《半导体技术》2004,29(5)
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test. 相似文献
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The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation. 相似文献
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The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high. 相似文献
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Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible. 相似文献
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GU Min-fen LIANG Zhong-cheng WANG Ren-zhou DONG Xiang-mei ZHANG Pei-ming CHEN Jia-bi 《光电子快报》2008,4(2):150-152
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. 相似文献
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Qi-jiang Ran Pei-de Han Yu-jun Quan Li-peng Gao Fan-ping Zeng Chun-hua Zhao 《光电子快报》2008,4(4):239-242
This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel's. 相似文献
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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. 相似文献
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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. 相似文献
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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. 相似文献