基于FPGA控制的多电平电压质量调节装置研究

研究了基于4 H桥级联9电平结构的电压质量调节装置,采用现场可编程门阵列和数字信号处理控制,针对电力系统中出现的各种电压质量问题,提供了综合的解决方案。该方案能够对电力系统中发生的电压暂升、电压暂降、电压谐波、电压波动等问题进行复合补偿,从而保证系统的电压质量。最后设计研制了0.1 MVA/400 V低压样机,对于各种电压质量问题进行试验,并对数据结果进行分析,结果表明本装置可以有效补偿各种电压质量问题。     

Ultra Storage-Efficient Time Digitizer for Pseudorandom Single Photon Counter Implemented on a Field-Programmable Gate Array

Pseudorandom single photon counting is a novel time-resolved optical measurement method, which is advantageous over convention techniques in terms of data-acquisition speed and system cost. As a critical component of the pseudorandom single photon counter, the photon arriving time digitizer should be storage efficient for a high photon counting rate, while maintaining good time accuracy. We report an ultra storage-efficient time digitizer for a pseudorandom single photon counter in this paper, which is based on the asynchronous serial communication and can store the arriving time of every photon in 1-b memory space. In addition, a novel comb-wave modulator is proposed to achieve the dc balance required for asynchronous serial communication. Our prototype implemented on field-programmable gate arrays provides a time resolution of 400 ps. It can register up to 4.2-Giga photon arriving time tags with 1024 $times$ 32-b memory space.      

利用现场复杂可编程门阵列产生PWM控制脉冲的方法

以有源滤波系统中PWM脉冲的生成原理为基础 ,阐述了一种基于DSP -FPGA数字系统的PWM控制脉冲生成方法 ,并给出了仿真及实验结果     

Differential Near-Field Scanning Optical Microscopy Using Sensor Arrays

In this paper, we introduce a new aperture-type near-Held scanning optical microscopy (NSOM) imaging concept that relies on specially designed large-area (e.g. >200 nm times 200 nm) aperture geometries having sharp corners. Unlike in conventional NSOM, the spatial resolution of this near-field imaging modality is not determined by the size of the aperture, but rather by the sharpness of the corners of the large aperture. This approach significantly improves the light throughput of the near-field probe and, hence, increases the SNR. Here, we discuss the basic concepts of this near-field microscopy approach and illustrate both theoretically and experimentally how an array of detectors can be utilized to further improve the SNR of the near-field image. The results of this work are particularly relevant for imaging of biological samples at a spatial resolution of < 50 nm with significantly improved image quality.     

Fabrication of Ferroelectric Gate Memory Device Using BLT/HfO2/Si Gate Structure

Ferroelectric gate FET's with BLT/HfO₂ structure were fabricated on 5-inch-scale Si wafer using well-refined CMOS compatible 0.8 μm-based fabrication processes for the first time. We obtained excellent device characteristics and good memory operations of the fabricated n-ch and p-ch MFIS-FET's, in which the memory window and on/off drain current ratio of typical p-ch memory device were measured to be 1.5 V at V_G of ±5 V and 8 orders-of-magnitude, respectively. We also confirmed by evaluating the gate voltage and gate size dependences of device properties that the fabricated devices showed quantitatively reasonable ferroelectric memory operations.     

用单片机实现闸阀门开度的检测

用单片机实现闸阀门开度检测,实现PLC与闸阀门开度检测装置之间的连接。不仅具有成本低、PLC编程简单的特点,而且具有高可靠性。     

Analysis of Gate Dielectric Stacks Using the Transmitting Boundary Method

We present simulations of tunneling current through layers of high-κ dielectrics using the Tsu-Esaki model and the quantum transmitting boundary method (QTBM) to estimate the transmission coefficient. In contrast to transfer-matrix based methods, which suffer from numerical instabilities due to rounding errors, the QTBM is numerically stable even for large stacks and is suitable for implementation in device simulators. The method is used to investigate the tradeoff between conduction band offset and permittivity in alternative high-κ materials.     

磁传感器阵列测量瞬态电流的新算法

不借助如聚磁环等辅助装置,直接利用磁传感器组来测量载流导体周围的磁场,进而反算待测电流是电力系统大电流测量的一种新思路。为了快速计算电流,尤其是电力系统中常见的瞬态电流,同时确保测量的准确性,文中研究了测量频带内磁场分布的动态特性,在时域中建立了基波电流与磁场幅值对应关系的瞬态电流计算模型。以三相矩形母排系统为例,研究了该测量模型适用的磁传感器组放置区域,并分析了误差的来源。最后利用实验验证了该模型的有效性。     

The Advantages of Using Saturable DC Series Motors Fed from Solar Photovoltaic Arrays

This paper presents a method for increasing the daily output mechanical energy supplied by DC motors directly connected to solar cell arrays (SCA). Without any interfacing circuitry between the PV-array and the DC series motor, an increase of about 10% in the mechanical energy can be achieved. The procedure is based on the use of series DC motors with nonlinear magnetic circuits so that these motors will be driven into their saturation region during their normal operation. It will be shown that through properly selecting the parameters of the motor’s magnetization characteristics (initial mutual inductance and the flux saturation level), an improved matching between the PV-array and the DC motor will be possible.     

平移法整体迁移铁塔的应用

介绍在地形环境满足要求的情况下,用平移法整体迁移铁塔的具体施工方法。实际应用也证明,用平移法整体迁移铁塔的停电时间短,安全性高,节约投资,经济效益和社会效益显著,值得相关部门的推广和应用。     

遗传算法在水轮机非固定模式导叶关闭规律中的应用

水轮机非固定模式导叶关闭规律是指按水轮机初始工况参数适时地确定最佳导叶关闭方式。这种适时的水轮机导叶关闭方式对于水电站大波动过渡过程具有较好的参数控制作用,能在不改变任何基础设施的前提下降低水电站过水系统最高水锤压力和机组转速,给水电站的运行带来较大的经济效益。在对非固定模式导叶关闭规律的优化中遗传算法有较高的优化效率,其中主要表现在算法简单、全局搜索性好、收敛性高、优化结果稳定。     

用变时基技术进行弧形钢闸门的模态试验分析

使用变时基传递函数模态分析技术对龙羊峡水电站表孔溢洪道弧形钢闸门进行模态试验和分析,极大地提高了大型结构的传递函数的分析精度。试验结果表明,龙羊峡水电站1、2号门具有相似的振动形态。     

用变时基技术进行弧形钢闸门的模态试验分析

使用变时基传递函数模态分析技术对龙羊峡水电站表孔溢洪道弧形钢闸门进行模态试验和分析,极大地提高了大型结构的传递函数的分析精度.试验结果表明,龙羊峡水电站1、2号门具有相似的振动形态.     

Calculation of Direct Tunneling Current through Ultra-Thin Gate Oxides Using Complex Band Models For SiO2

We report the calculation of gate leakage currents through the ultra-thin gate oxides (2.6–3.4 nm) in MOSFETs. We simulate J-V characteristics for the direct tunneling of valence electrons and inversion layer holes, which are measured using a charge separation technique. A two-band model is employed to express the complex band structure of the gate oxide, and its validity is discussed by calculating the complex band structure of -cristobalite based on the second nearest neighbor sp ³ s* tight-binding scheme.     

应用门循环神经网络的变电站智能记录分析装置信息配置方法

为了节约人力资源,提高智能变电站二次设备数据输出端口地址信息在智能记录分析装置中的配置效率,提出了基于门循环单元神经网络的智能变电站二次设备端口地址信息的自动配置方法.首先,根据变电站二次设备端口描述文本的特点进行文本预处理;然后,利用word2vec模型对文本进行词向量表示及语义关联分析;最后,设计了基于门循环单元神...     

基于强度折减法的人工岩质边坡稳定性分析

边坡的稳定性问题关系到人类生命财产安全以及工程本身的安全和效益,对其稳定性进行分析评价具有重要意义。本文通过FLAC3D数值模拟软件、采用强度折减法对武安发电厂的人工岩质边坡进行了稳定性分析。列举了边坡稳定性分析的三种失稳判据,并计算了相应的安全系数。分析结果表明,该人工岩质边坡基本稳定,与极限平衡方法比较,所得结果相差不大,说明强度折减法应用于边坡稳定性分析是可行的。此外,本文对该人工边坡的施工方案进行了重新设计。经验算,设计后的边坡依然处于稳定状态,但却大大减少了边坡的开挖量,提高了工程的经济效益。     

质谱检漏技术在发电机氢气检漏中的应用

介绍了利用(?)质谱检漏仪检测发电机漏氢的方法,对几种常用的找满方法进行了对比,说明了漏氢的常见原因,总结了经验和教训,并详细论述了用UL200检漏仪检测和处理一台300MW发电机组端盖内漏氢的过程。     

Simulation and Optimization of Diode and Insulated Gate Bipolar Transistor Interaction in a Chopper Cell Using MATLAB and Simulink

Recently, a simulation method for power electronic devices has emerged, which has high accuracy and short run times based on a Fourier model of the device physics. This paper describes the use of the Fourier models for diodes and insulated gate bipolar transistors (IGBTs) and implementation in MATLAB and Simulink in a formal optimization strategy. In particular, this paper investigates coupled circuit, diode, and IGBT behavior. Conclusions are drawn concerning device loading and circuit design, particularly the role of stray inductance.