变频器在工业锅炉风机上的应用

文章介绍了变频调速器在工业锅炉风机上的应用，着重计论了变频调速系统的闭环控制方案和工作原理。     

变频器在轧钢生产中的应用

文章介绍了ABB变频调速器在轧钢生产中的应用，着重讨论了变频调速系统的闭环控制方案和工作原理。     

基于ARM的柴油机电子调速器研究

将嵌入式系统应用到船舶柴油机电子调速器的控制系统中,提出了采用LPC2129控制的柴油机数字式电子调速器。给出了系统的硬件总体结构设计和软件设计流程。硬件方面阐述了以LPC2129为核心所构建的硬件各组成部分。针对嵌入式系统的特点进行了电子调速器嵌入式控制系统的研究,实现了控制系统中的PID控制算法,实验表明,能克服传统机械式诸多方面的缺点,满足大多数中高速柴油机不同工况下的调速要求。     

电梯专用矢量控制变频调速器设计

简要介绍了一种电梯专用的、矢量控制变频调速器的原理和技术方案。该变频调速器采用转差频率型矢量控制，在电动机转子磁通的旋转坐标上，对电动机进行运算控制，使交流异步电动机具有直流电机的调速性能，即使在零速时，也能输出额定转距，此外，由于功率因素始终接近于１，比普通调压调速方式节能３０％以上。     

浅析直流调速系统故障和处理方法

现如今直流调速器已经逐渐由传统模拟控制方式向数字控制方式进行转变,具有较为强大的远程监控和故障报警保护功能。直流调速器具有较为复杂的系统,有些技术人员在直流电机或直流调速器出现故障不能够快速的找出故障点和解决问题。在某些故障抢下,技术人员需要正确的方法和清晰的思路,就能够在很短的时间内找出问题。如何对直流调速器和直流电动机的故障快速的诊断和检查,在此笔者将自身经验与大家分享。     

VEC变频调速器在空气压缩机上的应用

本文介绍了VEC变频调速器在空气压缩机上的应用,实践证明,变频调速可以十分方便地进行连续调节,能保持压力、流量等参数的稳定,大大提高了压缩机的工作效率及性能。     

与压缩机空调并联冗余的调速节能系统

基站/机房数控调速新风/排热节能系统采用PLC数字控制,该系统通过比较新风与压缩机空调的能效比,选择新风或排热运行模式,并始终与压缩机空调同时工作、并联冗余。该系统采用袋式除尘、压差传感器、烟感传感器、风速计、消音烟囱,以及夜间降噪运行,能够适应室内外各种工况,实现安全、合理运行,并且显著提高节能效率,成倍延长维护周期。     

基于单片机的无线温控电风扇调速器设计

本系统以AT89C51单片机为核心,结合传感器、无线通信、可控硅等技术,利用环境温度变化来自动控制电风扇转速的大小,实现了多档无线温控电风扇全自动调速控制,较好地把智能控制技术应用到了家用电器控制系统中.该调速器性能稳定、控制准确、节能节电;利用软件技术实现电风扇风速调级和开停机控制,增强了抗干扰性.适用于依靠电风扇散热来降温的任一控制系统中.     

DEH数字电液调速系统在莱钢12MW汽轮发电机组中的实践与应用

针对莱钢原有发电机组机械调速的不稳定因素,提出改造方案,进行数字电液调速系统改造,实践证明,效果良好.     

基于89C51的SPWM变频调速系统的设计

伴随着电子半导体元器件的快速发展,交流电动机的转速控制出现一场深刻的技术改革,同时各种高性能配置的微处理器不断扩大应用范围,使得这场技术改革可以进入全数字化的发展进程,通过各种类型电力半导体器件搭建的变频调速系统逐步替代包含直流电动机调速系统以内的各种调速系统。变频调速系统以其调速精度高、控制范围宽广、响应速度快捷、保护功能全面,过载能力强、节能显著、使用维护方便等各种优点,已经广泛地应用在电力系统、交通运输、生产制造等各个经济领域。     

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.     

Cost-effective test solutions for smart card and other integrated flash applications

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.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

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.     

An improved parallel thinning algorithm with two subiterations

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.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

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.     

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.     

Study of waveguide coupling efficiency in hybrid silicon lasers

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.     

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.     

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.