单相在线式UPS的全数字化控制实现

文章介绍了在线式UPS的基本原理以及逆变器的SPWM调压方法,选用DSP实现UPS的数字化控制和更准确更快速的锁相环控制。对输出电压用数字PID来改善逆变控制的动态性能,得到稳定的输出电压。     

UPS通信电源系统数字化控制技术研究

随着通信行业的高速发展和设备的更新换代,对UPS通信电源系统也提出了更高的要求。传统的模拟控制技术已不能满足需要,数字化控制技术的应用使UPS系统性能得到很大提升。本文对UPS系统电路结构及数字化控制技术进行研究分析,对提高UPS的性能具有重要意义。     

浅谈UPS电源中静态开关的故障

为降低在线式UPS电源在执行市电旁路供电与逆变器供电切换控制时的故障率,绝大多数在线式UPS电源都采用了锁相同步控制回路。额定输出功率较小的在线式UPS电源多采用快速继电器作为转换元件。当它在执行市电供电与逆变器供电切换操作时,其后接负载的供电将会出现明显的电压输出波形扰动,甚至会产生长达几毫秒的供电中断,不能真正实现不间断供电。虽然从技术和使用的角度来看,市电供电中断时间不     

基于DSP及FPGA的UPS设计

目前,UPS（不间断电源）已被广泛应用到各行各业,人们对UPS的性能也提出了越来越高的要求。文章介绍了基于LF2407A及FPGA的数字在线式UPS的设计,采用DSP芯片满足了UPS逆变器数字控制算法实时性高的要求,并使硬件系统模块化、控制灵活、通讯方便、可靠性高。同时,利用FPGA器件实现键盘扫描及液晶显示接口等,进一步简化了电路设计。     

宝星推出新款高频UPS

Venus金星系列是一款全智能型高频在线式UPS,采用DSP高频在线式的架构设计,能有效阻隔异常电源对负载的冲击,同时确保输出电源的稳定性和可靠性,让负载安全的运行。     

英威腾HT11系列在线式1～3kVA高性能UPS

HT11系列在线式UPS采用双变换架构设计，DSP数字化控制技术，具有超高的输入／输出功率因数，可自动适应输入频率，具备智能化的电池管理、本地／远程网络监控管理和EPO（紧急关机）等功能。     

基于STM32的智能化数字化在线式UPS系统设计

针对高校电子类专业实验室对电能质量日益增高的要求,提出了基于以ARM Cortex2 M3为内核的STM32F103RBT6控制的数字化、智能化在线式UPS电源,给出了各模块的硬件设计方案和软件处理流程。相比较于其他控制方式的UPS,其具备稳定性较高,结构简单,效率高,保护功能齐全,智能化程度较高等系列优势。     

UPS电源中SPWM控制技术的研究

论述了目前UPS电源中所用到的一些SPWM控制方法，重点介绍了一种基于PIC16F73单片机产生SPWM控制波形的方法，以及这种方法应用于在线式纯正弦波UPS电源系统中的可行性。     

在线式UPS原理与使用

UPS按照工作方式可分为:在线式(ONLINE)、在线互动式(LINE INTERACTIVE)、后备式(OFF LINE)3种.由于在线式UPS有着其他UPS电源和稳压电源无法比拟的优点,使得在线式UPS在各行业得到了广泛的应用.     

基于DSP的异步电动机直接转矩控制系统的实现

直接转矩控制技术是目前最为优良的交流电机控制技术,数字信号处理器（DSP）的高速运算和实时处理功能为直接转矩控制技术的数字化提供了基础。本文介绍了直接转矩控制的基本原理及TMS320LF2407 DSP的特点,给出了以TMS320LF2407 DSP为核心的异步电动机直接转矩控制系统的设计方案及软硬件的实现,同时对直接转矩控制系统进行了实验和仿真,验证了直接转矩控制技术的优良性能。     

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.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

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.     

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.     

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.     

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.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

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.