关于分立磁件集成判据的研究

磁路集成技术已在电力电子装置中取得了广泛的应用.提出了一种新的系统化集成磁件设计方法.此外,还提出了一种对于3个以上磁件可否集成的评判标准.最后通过对不对称半桥加倍流整流电路中3个分立磁件进行集成设计,验证了该方法简单、易行.     

新一代智能变电站开关综合监测装置研制

针对新一代智能变电站建设需求及国家电网公司对新一代智能变电站集成化设备的技术要求,文中设计了一种适用于新一代智能变电站的高压开关/GIS功能整合型监测装置。根据功能特点将分立的机构监测IED、测量IED、监测主IED、避雷器监测IED功能进行整合,完成间隔内高压开关的状态监测、就地诊断、二次设备在线监测功能。试验及现场运行结果表明,设计的装置有效减少了间隔监测装置的数量,具有很好的应用前景和推广价值。     

基于可缩放矢量图形和构件技术实现电网线损管理系统

在分析电网运营实际需求的基础上,提出了基于可缩放矢量图形（scalablevectorgraphics,SVG）和构件技术建设图、模一体化电网线损管理系统的解决方案,给出了高电压等级和低电压等级的线损计算模型;介绍了电网模型和图、模一体化设计方法,以及线损统计计算、分区域统计分析等系统主要功能,讨论了SVG技术、构件技术、动态分析报表等关键技术的实现方法。该系统能够提高线损管理水平,减少不明电量损失,促进节能降耗。     

The Parametric Yield Enhancement of Integrated Circuits

Even where a satisfactory circuit design has been achieved, it is often the case that, owing to variations in the manufacturing process, some of the samples of a mass-produced circuit will violate the specifications on performance so that the manufacturing yield is less than 100%. Such an undesirable effect can, however, be minimized or even eliminated by redesign of the circuit to the extent of changing parameter values while retaining the original circuit topology. For discrete component circuits algorithms are available to achieve such redesign. the special characteristics of integrated circuits, however, are such that these methods are unsuitable as they stand. Two new algorithms for handling the yield enhancement of integrated circuits are described and their successful application is illustrated in the context of two-stage CMOS op amps.     

一种配电网单相接地故障综合选线方法

为了充分利用配电网单相接地故障时的故障信息,以提高选线装置的正确选线率,提出了一种综合选线判据的方法。该法将反映故障稳态分量的选线判据、暂态分量的选线判据和利用外加诊断信号的选线判据有机融合,以变电站母线所带出线为研究论域,各单一选线判据为条件属性,离散化的各故障特征量为条件属性值,形成故障信息表并对其进行论域缩减,最后利用决策规则形成决策表,从决策表的决策属性中找到综合选线结果。仿真验证了该综合选线的优越性。     

分立磁件集成判据及集成磁件设计

在比对集成磁件和分立磁件设计流程的基础上,提出了一套判定2个或者3个以上分立磁件可否集成的判据,对在集成磁件设计当中出现的磁通相互抵消现象,采用几何方法给出了直观的解释和合理的解决方案。分析了集成磁件复现分立磁件电流波形的可能性及条件。对于集成磁件引起的电路拓扑出现电流环路问题进行了深入讨论。在这套理论的基础上,提出采用绕组遍历法设计集成磁件的计算机方法。通过对采用倍流整流的半桥拓扑中3个分立磁件的集成设计,验证该设计方法直观、有效。     

基于实时监控的沥青混凝土心墙坝坝面碾压施工仿真研究

目前沥青混凝土心墙坝坝面碾压施工仿真主要考虑碾压机械的工作效率,没有将实际的施工数据融入到仿真模型中,从而降低了仿真的可靠性。针对此问题,本文将碾压过程实时监控引入仿真模型,基于实时监控技术的碾压施工数据,通过数理统计方法,获得贴近实际施工的仿真参数;同时,结合离散事件仿真方法,建立沥青混凝土心墙碾压施工过程的精细化仿真模型;最后,通过Monte Carlo方法计算得到填筑单元的碾压历时和区段初碾合格率。以西南某在建沥青混凝土心墙坝工程为实例进行仿真计算分析,通过置信度检验方法对仿真模型进行验证,并通过局部灵敏度分析的方法对仿真参数进行灵敏度分析,为现场坝面碾压施工的指导和工程进度的控制管理提供技术支持。     

嘉兴电网SCADA/EMS/DTS/DMS/MIS的一体化管理

随着我国电力工业的发展,包括配电系统自动化在内的城网建设和改造已提上了日程。含高压主网和中我 配网的地区级嘉兴电网,装备和正在装置ＳＣＡＤＡ、ＥＭＳ、ＤＴＳ、ＤＭＳ、ＭＩＳ等多种自动化装置和系统。章在对其功能进行描述的基础上,就众多自动化装置和系统的一体化管理问题－－从信息共享、应用地,到方法共享,进行了分析和讨论。     

基于生命周期法和碳权交易的综合能源系统低碳经济调度

随着综合能源系统的不断发展,如何进一步提升综合能源系统的经济和环境效益是综合能源系统的重要研究内容.除了各发电机组存在大量的碳排放外,新能源机组及电储能设备生产建设和运输过程也存在大量碳排放,也应计入系统的总碳排放量中.为此文中基于含电热负荷需求的综合能源系统,分析了系统各机组的碳排放量,并运用生命周期法分析综合能源系...     

Partial fraction expansion–based realizations of fractional-order differentiators and integrators using active filters

Approximations of the fractional-order differentiator and integrator operators s^±r are proposed in this work. These approximations target the realization of these operators using standard active filter transfer functions. Hence, circuit implementations in integrated circuit form or in discrete component form are significantly facilitated. Complementary metal-oxide-semiconductor (CMOS) realizations of the proposed approximations are given and validated via simulations using the AMS 0.35 μm CMOS technology, while experimental results using operational amplifier circuits are tested and confirm the proposed theory.     

A Millimeter-Scale Electric Generator

The research presented in this paper concerns the design, construction, and testing of an electrical generator intended for interface with a MEMS internal combustion Wankel engine. The engine and the generator are integrated into a single unit by utilizing the engine rotor as the generator rotor. The design allows for thermal insulation between the stator and the combustion chamber, simple assembly of the engine and the generator, and excellent utilization of copper in the generator winding. The majority of the generator structure is built from discrete millimeter-scale components, with only the rotor being microfabricated. Prototype construction and testing are described; a peak open-circuit voltage of 2.63 V and a maximum power output of 375 $muhbox{W}$ at 13.3 kr/m are reported.      

基于PCA和DP的电力施工企业动态联盟

针对我国电力施工企业现状,将动态联盟思想引入到电力施工企业之中,阐述了电力施工企业联盟范围和构造方法,提出了基于主成分分析（principle component analysis,PCA）和动态规划（dynamic programming,DP）的动态联盟构造方法。利用PCA法将多个指标（如人力、资金、时间、技术等）转化为少数几个综合指标（主成分,如综合成本、实物成本等）,一般情况下只选取第一主成分;再用DP法寻找最优联盟结构。算例结果验证了该方法的有效性,可为我国电力施工企业的发展提供思维框架和方法。     

基于混沌理论的控制轨道函数构造

简述了混沌理论和方法在控制过程中的应用。利用非线性函数的混沌性质，通过部分离散采样值，对一类控制过程演化函数提出一种新的构造方法，得到方程的代数形式，为参数选择、轨道摄动提供了基础。提出了构造过程和构造方程形式的析出定理的理论证明，提供了构造函数的误差公式。研究表明，对于具有有限项多项式型演化函数的控制过程，如果离散采样值满足条件，则构造函数没有模型误差。     

基于小波广义回归神经网络耦合模型的月径流预测

针对中长期水文预报方法预测结果精度低的问题,将离散小波变换(DWT)与广义回归神经网络(GRNN)耦合,建立了月径流预测模型。通过DWT处理将原始月径流序列分解重构为确定性成分和随机性成分两个分量,对两个分量的GRNN模型预测结果叠加作为预测值的方法称为WGRNN1模型。将WGRNN1模型与剔除随机序列的GRNN模型(WGRNN2)和不进行离散小波变换的GRNN模型结果进行对比,采用平均绝对误差(MAE)、确定性系数(DC)和相关系数(R)为模型评价指标。将模型应用于黑河干流莺落峡站的月径流预测,结果表明:模型WGRNN2的评价指标优于WGRNN1,且这两个模型预测效果都优于GRNN模型。说明与离散小波变换的耦合可以提高GRNN模型对月径流的预测精度,同时剔除随机成分的小波广义回归神经网络模型有更好的预测效果,可应用于实际生产。     

基于离散小波变换和模糊K-modes的负荷聚类算法

为了研究智能电网背景下用户的用电模式,考虑到现有聚类算法的不足,提出了一种基于离散小波变换的模糊K-modes聚类算法。利用离散小波变换将时域的负荷曲线转换到频域,从而将负荷曲线的不同特征隔离在不同的频域水平,并利用低阶近似的思想选取原始曲线的有效分量曲线;对所选的分量曲线进行趋势编码,将连续负荷数据转化为离散类属性数据;基于平均密度确定初始聚类条件,利用模糊K-modes聚类算法对曲线进行形态聚类,得到负荷曲线模板;将所提算法与传统K-means算法及层次聚类算法进行比较,从而验证了所提算法的有效性。     

An integrated flywheel energy storage system with homopolar inductor motor/generator and high-frequency drive

The design, construction, and test of an integrated flywheel energy storage system with a homopolar inductor motor/generator and high-frequency drive is presented in this paper. The work is presented as an integrated design of flywheel system, motor, drive, and controller. The motor design features low rotor losses, a slotless stator, construction from robust and low cost materials, and a rotor that also serves as the energy storage rotor for the flywheel system. A high-frequency six-step drive scheme is used in place of pulsewidth modulation because of the high electrical frequencies. A speed-sensorless controller that works without state estimation is also described. A prototype of the flywheel system has been demonstrated at a power level of 9.4 kW, with an average system efficiency of 83% over a 30000-60000 r/min speed range.     

三类宽带高增益超声检测调理电路设计与比较

针对医用宽带超声小信号检测的不同效益需求,以分立元件、分立元件与集成运放结合、专用集成芯片3类可变增益放大电路为核心,分别给出不同类型的超声检测调理电路设计方案,并对其优缺点和适用范围进行了讨论。最后以PR5800超声收发器作为标准源,测试了基于放大器AD8334的实验电路,对脉冲超声信号进行放大和滤波,获得稳定的80 dB放大波形,并通过计算其信噪比换算了电路的输入噪声密度为0．7 nV／ Hz。所述电路能很好地达到80 dB最大增益、30 M Hz带宽＠80dB、输入噪声密度＜5 nV／ Hz的设计要求,为超声前端设计的成本、灵活度、方便性等问题提供了很好的参考。     

Detection of mechanical imbalances of induction machines without spectral analysis of time-domain signals

Mechanical rotor imbalances and rotor eccentricities are reflected in electric, electromagnetic, and mechanical quantities. Therefore, many surveillance schemes determine the Fourier spectrum of a single line current in order to monitor the motor condition. Mechanical imbalances give rise to two first-order current harmonics. Due to the interaction of the currents and voltages, both these current harmonics are also reflected by a single harmonic component in the frequency spectrum of the electric power. This single component is easier to assess than both the current harmonics. The technique proposed in this contribution evaluates this imbalance-specific modulation of the electric power. The proposed approach does not determine the Fourier spectrum of a time-domain signal, though. First, the imbalance specific oscillation of the electric power is extracted by a bandpass filter. Then, the averaged pattern of this component is determined by means of an angular data clustering technique. In that way, the oscillation of the electric power in the time domain becomes mapped into a discrete waveform in an angular domain. The amplitude of the fundamental harmonic of these discrete data serves as the imbalance indicator of the proposed scheme. This technique, therefore, overcomes small load and slip fluctuations. Measured results of a mechanically unbalanced machine and a case of combined static and dynamic eccentricity are presented.     

一种新型无刷直流电机转子位置检测方法

提出一种新的基于假中性点电压交流分量积分过零点的转子位置检测方法。通过对假中性点电压信号特性的分析,提出假中性点电压交流分量积分过零点对应电机换相时刻。该方法低速检测范围更宽,实现简单,不要求无刷直流电机具有理想的梯形波磁场,在直流母线电压低的中小功率应用场合尤其具有技术优势。实验验证了方法的有效性。     

基于综合能源的区域用能可靠性评估研究

综合能源系统的区域用能可靠性评估是保障其安全可靠运行的重要基础.文章提出了一种基于马尔可夫模型多组件的综合能源可靠性评估方法.针对综合能源系统出现大量组件问题,建立基于马尔可夫模型综合能源供能子系统随机状态模型,对RBTS-Bus2系统模型进行可靠性评估,计算其可靠性指标.根据该评估方法,可以确定光伏、风力、储能、冷热电联供和市电、用户的负载等在综合能源系统中需求比重.案例分析结果表明,综合能源供应体系能有效提升系统的可靠性,但也存在边界效应问题,有待进一步研究解决.