选择性有源滤波器治理12脉波整流器的谐波

文章介绍12脉波整流器应用选择性有源滤波器抑制谐波电流和补偿无功,采用基于瞬时功率理论的谐波和无功电流检测方法。对有源滤波器和负荷系统进行仿真,并对仿真结果进行详细分析。仿真结果表明：基于瞬时功率理论的谐波和无功电流检测方法可以准确、实时地检测出三相电流中的任意次谐波及无功电流,有源滤波器抑制11次和13次谐波电流,并补偿无功。     

新型三相三线制并联有源滤波器的滑模控制方法

为了提高有源滤波器的谐波补偿效果,设计了一种新型滑模控制器,用于三相三线制并联有源滤波器的参考电流跟踪控制.谐波电流检测方法采用基于瞬时无功功率理论的谐波电流检测方法,能快速、准确的检测出负载电流中的谐波分量.直流侧电压控制方法采用PI控制方法实现.Simulink仿真结果显示,与传统的滞环比较控制方法相比,所设计的新型滑模控制方法能够有效的降低跟踪误差,提高有源滤波器的谐波补偿效果.     

基于TMS320LF2812的并联型有源电力滤波器的设计与实现

针对谐波抑制和无功补偿的问题,对有源电力滤波器进行一系列研究,阐述了有源电力滤波器的基本原理以及控制策略。基于TMS320LF2812设计了有源电力滤波器,包括DSP控制板、电压采样电路,电流采样电路以及IPM功率单元的设计,并给出了有源电力滤波器的软件设计。最后利用MATLAB仿真软件对所涉及的有源电力滤波器进行仿真,验证了有源滤波器系统的正确性以及谐波补偿电流和滞环比较控制模块的有效性。     

电力有源滤波器在供电系统中的应用（续）

电力有源滤波器在供电系统中的主要应用是补偿电网中的谐波和无功功率,依此改善交流电源的供电质量。文中介绍了电力有源滤波器的电路结构以及控制方式。给出了电压型电力有源滤波器、电流型电力有源滤波器、多模式电力有源滤波器以及混合型电力有源滤波器的电路结构,并重点介绍无功电流和谐波电流的检测、逆变器直流侧电源电压的控制以及混合型电力有源滤波器的控制方案,最后给出了电力有源滤波器的补偿特性。     

基于MATLAB的有源滤波器研究

本文利用瞬时无功功率理论进行有源滤波器的仿真设计。仿真结果表明基于瞬时无功功率理论设计的有源滤波器能够有效检测出高次谐波分量,并达到消除谐波和进行无功补偿的目的。     

基于磁通补偿原理的有源电力滤波器

根据电力电子系统的磁通补偿原理。介绍了一种基于磁通补偿原理和并联变压器谐波阻抗控制的有源电力滤波器的设计方案,给出了采用单位功率因数控制策略控制有源电力滤波器的基本结构和谐波电流检测方法。同时通过仿真实验,给出了对滤波器进行补偿的补偿电流和系统电流的波形。     

补偿电铁谐波及无功电流的有源滤波器的研究

研究应用于补偿电铁谐波及无功电流的单相有源滤波器,基于鉴相原理的谐波及无功电流检测法适合于作为电铁谐渡及无功电流的检测方法,改进的三角波调制电流控制方法能对电铁系统中的谐波及无功电流起到很好的补偿作用.仿真结果表明有源滤波器能够达到综合补偿的目的.     

电力有源滤波器在供电系统中的应用

电力有源滤波器在供电系统中的主要应用是补偿电网中的谐波和无功功率,依此改善交流电源的供电质量。文中介绍了电力有源滤波器的电路结构以及控制方式。给出了电压型电力有源滤波器,电流型电力有源滤波器,多模式电力有源滤波器以及混合型电力有源滤波器的电路结构,并重点介绍无功电流和谐波电流的检测,逆变器直流侧电源电压的控制以及混合型电力有源滤波器的控制方案,最后给出了电力有源滤波器的补偿特性。     

有源电力滤波器两种检测算法的比较研究

文章研究了有源电力滤波器的两种谐波电流检测算法,ip-iq法对负载电流中的谐波进行全部检测,基于用户侧谐波和无功补偿的检测法仅对用户自身造成的谐波进行检测。仿真结果表明,通过APF补偿后,前者电源电流为正弦波,后者电源电流和电源电压保持相同的畸变率,波形相似。     

基于PWM技术的微电网谐波抑制技术的研究

电力电子变换器、非线性负载以及分布式电源的广泛使用,都不同程度的给微电网带来谐波污染,运用基于PWM技术的有源滤波器,对微电网的谐波进行抑制,该方法先通过检测法对谐波进行快速有效的检测,通过滞环比较PWM电流控制法来产生补偿电流,最后利用MATLAB/SIMULINK软件搭建仿真平台对微电网的谐波进行仿真研究以验证其滤波效果。     

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.     

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.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks